Novel fructosyltransferases

ABSTRACT

The present invention describes two novel proteins having fructosyltransferase activity. Both enzymes are derived from lactobacilli, which are food-grade micro-organisms with the Generally Recognized As Safe (GRAS) status. One of these proteins produces an inulin and fructo-oligosaccharides, while the other produces a levan and fructo-oligosaccharides. According to the invention lactobacilli capable of producing an inulin and/or a levan and/or fructo-oligosaccharides using one or both of the fructosyltransferases can be used as a probiotic or a symbiotic.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part application of U.S. application Ser. No. 09/995,587, filed on Nov. 29, 2001, which is a continuation-in-part application of U.S. application Ser. No. 09/604,958, filed on Jun. 28, 2000, which claims priority from European Application No. 00201872.9 filed on May 25, 2000.

[0002] The present invention is in the field of enzymatic production of biomolecules. The invention is particularly concerned with two novel fructosyltransferases derived from lactobacilli and with a process for recombinant production of the enzymes and for the production of useful levans, inulins and fructo-oligosaccharides from sucrose.

BACKGROUND OF THE INVENTION

[0003] Lactic acid bacteria (LAB) play an important role in the fermentative production of food and feed. Traditionally, these bacteria have been used for the production of for instance wine, beer, bread, cheese and yoghurt, and for the preservation of food and feed, e.g. olives, pickles, sausages, sauerkraut and silage. Because of these traditional applications, lactic acid bacteria are food-grade micro-organisms that posses the Generally Recognised As Safe (GRAS) status. Due to the different products which are formed during fermentation with lactic acid bacteria, these bacteria contribute positively to the taste, smell and preservation of the final product. The group of lactic acid bacteria encloses several genera such as Lactobacillus, Leuconostoc, Pediococcus, Streptococcus, etc.

[0004] In recent years also the health promoting properties of lactic acid bacteria have received much attention. They produce an abundant variety of exopolysaccharides (EPS's). These polysaccharides are thought to contribute to human health by acting as prebiotic substrates, nutraceuticals, cholesterol lowering agents or immunomodulants.

[0005] To date high molecular weight polysaccharides produced by plants (such as cellulose, starch and pectin), seaweeds (such as alginate and carrageenan) and bacteria (such as alginate, gellan and xanthan) are used in several industrial applications as viscosifying, stabilizing, emulsifying, gelling or water binding agents. Although all these polysaccharides are used as food additives, they originate from organisms not having the GRAS status. Thus they are less desirable than the exopolysaccharides of microorganisms, such as lactic acid bacteria, which have the GRAS status.

[0006] The exopolysaccharides produced by LAB can be divided in two groups, heteropolysaccharides and homopolysaccharides; these are synthesized by totally different mechanisms. The former consist of repeating units in which residues of different types of sugars are present and the latter consist of one type of monosaccharide. The synthesis of heteropolysaccharides by lactic acid bacteria, including lactobacilli, has been studied extensively in recent years. Considerably less information is available on the synthesis of homopolysaccharides from lactobacilli, although some studies have been performed. Homopolysaccharides with fructose as the constituent sugar can be divided into two groups, inulins and levans. Inulins consist of 2,1-linked β-fructofuranoside residues, whereas levans consist of 2,6-linked β-fructofuranoside residues. Both can be linear or branched. The size of bacterial levans can vary from 20 kDa up to several MDa. There is limited information on the synthesis of levans. In most detail this synthesis has been studied in Zymomonas mobilis and in Bacillus species. Within lactic acid bacteria, fructosyltransferases have only been studied in streptococci. So far no fructosyltransferases have been reported in lactobacilli.

[0007] In a recent report the Lactobacillus reuteri strain LB 121 was found to produce both a glucan and a fructan when grown on sucrose, but only a fructan when grown on raffinose (van Geel-Schutten, G. H. et al., Appl. Microbiol. Biotechnol. (1998) 50, 697-703). In another report the glucan and fructan were characterised by their molecular weights (of 3,500 and 150 kDa respectively) and the glucan was reported to be highly branched with a unique structure consisting of a terminal, 4-substituted, 6-substituted, and 4,6-disubstituted α-glucose in a molar ratio 1.1:2.7:1.5:1.0 (van Geel-Schutten, G. H. et al., Appl. Environ. Microbiol. (1999) 65, 3008-3014). The fructan was identified as a linear (2→6)-β-D-fructofuranan (also called a levan). This was the first example of fructan synthesis by a Lactobacillus species.

SUMMARY OF THE INVENTION

[0008] Two novel genes encoding enzymes having fructosyltransferase activity have now been found in Lactobacillus reuteri, and their amino acid sequences have been determined. These are the first two enzymes identified in a Lactobacillus species capable of producing a fructan. One of the enzymes is an inulosucrase which produces a high molecular weight (>10⁷ Da) fructan containing β(2-1) linked fructosyl units and fructo-oligosaccharides, while the other is a levansucrase which produces a fructan containing β(2-6) linked fructosyl units. The invention thus pertains to the enzymes, to DNA encoding them, to recombinant cells containing such DNA and to their use in producing carbohydrates, as defined in the appending claims.

DESCRIPTION OF THE INVENTION

[0009] It was found according to the invention that one of the novel fructosyltransferases (FTFA; an inulosucrase) produces a high molecular weight inulin with β(2-1) linked fructosyl units and fructo-oligosaccharides. The fructo-oligosaccharides synthesis was also observed in certain Lactobacillus strains, in particular in certain strains of Lactobacillus reuteri. However, the inulin has not been found in Lactobacillus reuteri culture supernatants, but only in extracts of E. coli cells expressing the above-mentioned fructosyltransferase. This inulosucrase consists of either 798 amino acids (2394 nucleotides) or 789 amino acids (2367 nucleotides) depending on the potential start codon used. The molecular weight (MW) deduced of the amino acid sequence of the latter form is 86 kDa and its isoelectric point is 4.51, at pH 7.

[0010] The amino acid sequence of the inulosucrase is shown in SEQ ID No. 1 (FIG. 1, amino acid residues 1-789). As mentioned above, the nucleotide sequence contains two putative start codons leading to either a 2394 (see SEQ ID No. 3) or 2367 (see SEQ ID No. 2) nucleotide form of the inulosucrase. Both putative start codons are preceded by a putative ribosome binding site, GGGG (located 12 base pairs upstream its start codon) or AGGA (located 14 base pairs upstream its start codon), respectively (see FIG. 1 and SEQ ID No. 4).

[0011] The present invention covers a protein having inulosucrase activity with an amino acid identity of at least 65%, preferably at least 75%, and more preferably at least 85%, compared to the amino acid sequence of SEQ ID No. 1. The invention also covers a part of a protein with at least 15 contiguous amino acids which are identical to the corresponding part of the amino acid sequence of SEQ ID No. 1.

[0012] Fructosyltransferases have been found in several bacteria such as Zymomonas mobilis, Erwinia amylovora, Acetobacter amylovora, Bacillus polymyxa, Bacillus amyloliquefaciens, Bacillus stearothermophilus, and Bacillus subtilis. In lactic acid bacteria this type of enzyme previously has only been found in some streptococci. Most bacterial fructosyltransferases have a molecular mass of 50-100 kDa (with the exception of the fructosyltransferase found in Streptococcus salivarius which has a molecular mass of 140 kDa). Amino acid sequence alignment revealed that the novel inulosucrase of lactobacilli has high homology with fructosyltransferases originating from Gram positive bacteria, in particular with Streptococcus enzymes. The highest homology (FIG. 2) was found with the SacB enzyme of Streptococcus mutans Ingbritt A (62% identity within 539 amino acids).

[0013] Certain putative functions based on the alignment and site-directed mutagenesis studies can be ascribed to several amino acids of the novel inulosucrase. Asp-263, Glu-330, Asp-415, Glu-431, Asp-511, Glu-514, Arg-532 and/or Asp-551 of the amino acid sequence of SEQ ID No. 1 are identified as putative catalytic residues. Noteworthy, a hydrophobicity plot according to Kyte and Doolittle (1982) J. Mol. Biol. 157, 105-132 suggests that the novel inulosucrase contains a putative signal sequence according to the Von Heijne rule. The putative signal peptidase site is located between Gly at position 21 and Ala at position 22. Furthermore, it is striking that the C-terminal amino acid sequence of the novel inulosucrase contains a putative cell wall anchor amino acid signal LPXTG (SEQ ID No. 5) and a 20-fold repeat of the motif PXX (residues 690-749 of SEQ ID NO: 1) (see FIG. 1), where P is proline and X is any other amino acid. In 15 out of 20 repeats, however, the motif is PXT. This motif has so far not been reported in proteins of prokaryotic and eukaryotic origin.

[0014] A nucleotide sequence encoding any of the above mentioned proteins, mutants, variants or parts thereof is also a subject of the invention. Furthermore, the nucleic acid sequences corresponding to expression-regulating regions (promoters, enhancers, terminators) of at least 30 contiguous nucleic acids contained in the nucleic acid sequence (-67)-(-1) or 2367-2525 of SEQ ID No. 4 (see also FIG. 1) can be used for homologous or heterologous expression of genes. Such expression-regulating sequences are operationally linked to a polypeptide-encoding nucleic acid sequence such as the genes of the fructosyltransferase according to the invention. A nucleic acid construct comprising the nucleotide sequence operationally linked to an expression-regulating nucleic acid sequence is also covered by the invention.

[0015] A recombinant host cell, such as a mammalian (with the exception of human), plant, animal, fungal or bacterial cell, containing one or more copies of the nucleic acid construct mentioned above is an additional subject of the invention. The inulosucrase gene (starting at nucleotide 41) has been cloned in an E. coli expression vector under the control of an ara promoter in E. coli Top10. E. coli Top10 cells expressing the recombinant inulosucrase hydrolyzed sucrose and synthesized fructan material. SDS-PAGE of arabinose induced E. coli Top10 cell extracts suggested that the recombinant inulosucrase has a molecular weight of 80-100 kDa, which is in the range of other known fructosyltransferases and in line with the molecular weight of 86 kDa deduced of the amino acid sequence depicted in FIG. 1.

[0016] The invention further covers an inulosucrase according to the invention which, in the presence of sucrose, produces a inulin having β(2-1)-linked D-fructosyl units and fructo-oligosaccharides. Two different types of fructans, inulins and levans, exist in nature. Surprisingly, the novel inulosucrase expressed in E. coli Top10 cell synthesizes a high molecular weight (>10⁷ Da) inulin and fructo-oligosaccharides, while in Lactobacillus reuteri culture supernatants, in addition to the fructo-oligosaccharides, a levan and not an inulin is found. This discrepancy can have several explanations: the inulosucrase gene may be silent in Lactobacillus reuteri, or may not be expressed in Lactobacillus reuteri under the conditions tested, or the inulosucrase may only synthesize fructo-oligosaccharides in its natural host, or the inulin polymer may be degraded shortly after synthesis, or may not be secreted and remains cell-associated, or the inulosucrase may have different activities in Lactobacillus reuteri and E. coli Top 10 cells.

[0017] It was furthermore found according to the invention that certain lactobacilli, in particular Lactobacillus reuteri, possess another fructosyltransferase, a levansucrase (FTFB), in addition to the inulosucrase described above. The N-terminal amino acid sequence of the fructosyltransferase purified from Lactobacillus reuteri supernatant was found to be QVESNNYNGVAEVNTERQANGQI (residues 2-24 of SEQ ID No. 6). Furthermore, three internal sequences were identified, namely (M)(A)HLDVWDSWPVQDP(V) (SEQ ID No. 7), NAGSIFGT(K) (SEQ ID No. 8), V(E)(E)VYSPKVSTLMASDEVE (SEQ ID No. 9). The N-terminal amino acid sequence could not be identified in the deduced inulosucrase sequence. Also the amino acid sequences of the three internal peptide fragments of the purified fructosyltransferase were not present in the putative inulosucrase sequence. Evidently, the inulosucrase gene does not encode the purified fructosyltransferase synthesizing the levan. The complete amino acid sequence of the levansucrase is shown in SEQ ID No. 11 and the nucleotide sequence is shown in SEQ ID No. 10. The levansucrase comprises a putative membrane anchor (see amino acids 761-765 in SEQ ID No. 11) and a putative membrane spanning domain (see amino acids 766-787 in SEQ ID No. 11). The fructan produced by the levansucrase was identified in the Lactobacillus reuteri culture supernatant as a linear (2→6)-β-D-fructofuranan with a molecular weight of 150 kDa. The purified enzyme also produces this fructan.

[0018] Additionally, the invention thus covers a protein having levansucrase activity with an amino acid identity of at least 65%, preferably at least 75%, and more preferably at least 85%, compared to the amino acid sequence of SEQ ID NO. 11. The second novel fructosyltransferase produces a high molecular weight fructan with β(2-6) linked fructosyl units with sucrose or raffinose as substrate. The invention also covers a part of a protein with least 15 contiguous amino acids, which are identical to the corresponding part of the amino acid sequence of SEQ ID No. 11. A nucleotide sequence encoding any of the above-mentioned proteins, mutants, variants or parts thereof is a subject of the invention as well as a nucleic acid construct comprising the nucleotide sequence mentioned above operationally linked to an expression-regulating nucleic acid sequence. A recombinant host cell, such as a mammalian (with the exception of human), plant, animal, fungal or bacterial cell, containing one or more copies of the nucleic acid construct mentioned above is an additional subject of the invention. The invention further covers a protein according to the invention which, in the presence of sucrose, produces a fructan having β(2-6)-linked D-fructosyl units.

[0019] In addition to the percentage of amino acid identity as referred to above, the proteins according to the invention preferably have a minimum degree of homology of at least 85%, preferably at least 90%, more preferably at least 95, 96, 97, even at least 98 or 99% with a given sequence, for example with amino acid sequences 22-789 of SEQ ID No. 1 or 22-792 of SEQ ID No. 11. A degree of homology as used herein and as commonly used in the art is equivalent to a degree of similarity as defined below, which means that two amino acids which are similar in both size and electronic structure but not identical, are treated as “conserved” substitutions of each other and thus are considered to fulfil the homology requirement. Conserved substitutions include substitutions among valine-leucine-isoleucine-methionine, alanine-valine, alanine-glycine, serine-threonine, phenylalanine-tyrosine-tryptophan, lysine-arginine-histidine, asparagine-glutamine-histidine, aspartic acid-glutamic acid. Methods to determine identity and similarity are codified in publicly available computer programs. Preferred computer program methods to determine identity and similarity between two sequences include e.g. the GCG program package (Devereux, J., et al., Nucleic Acids Research 12 (1):387 (1984)), BestFit, BLASTP, BLASTN, and FASTA (Altschul, S. F. et al., J. Mol. Biol. 215:403-410 (1990). The BLAST X program is publicly available from NCBI and other sources (BLAST Manual, Altschul, S., et al., NCBI NLM NIH Bethesda, Md. 20894; Altschul, S., et al., J. Mol. Biol. 215:403-410 (1990).

[0020] The invention also pertains to a process of producing an inulin-type and/or a levan-type of fructan as described above using fructosyltransferases according to the invention and a suitable fructose source such as sucrose, stachyose, raffinose or a fructo-oligosaccharide. The fructans may either be produced by Lactobacillus strains or recombinant host cells according to the invention containing one or both fructosyl transferases or by a fructosyltransferase enzyme isolated by conventional means from the culture of fructosyltransferase-positive lactobacilli, especially a Lactobacillus reuteri, or from a recombinant organism containing the fructosyltransferase gene or genes.

[0021] Where the fructans are produced by Lactobacillus strains, the strain may advantageously be in a non-growth state. This allows the production of the fructans to proceed without the necessity of supplying nutrients and other materials for supporting growth of the strains. In particular, the production can be performed by merely subjecting the sucrose or other fructose source such as raffinose to a medium containing the strains and withdrawing polysaccharides from the medium, or using the medium together with the polysaccharides to produce the desired end product. In a particular embodiment, the Lactobacillus strain may be immobilized on a carrier such as solid particles, filters, reactor walls and the like. The strains to be used may be native or recombinant, as long as they are capable of expressing at least one of the inulosucrase and levansucrase enzymes as described above. In addition, they may also contain an active glucansucrase enzyme and at the same time produce glucans. The polysaccharide production can be performed at neutral to slightly acidic conditions, in particular at a pH between 4 and 7, at temperatures between 25 and 60° C., preferably between 30 and 55° C. The fructose donor such as sucrose is preferably present at a level between 10 and 50 g/l.

[0022] Additionally, the invention concerns a process of producing fructo-oligosaccharides containing the characteristic structure of the fructans described above using a Lactobacillus strain or a recombinant host cell according to the invention containing one or both fructosyltransferases or an isolated fructosyltransferase according to the invention. There is a growing interest in oligosaccharides derived from homopolysaccharides, for instance for prebiotic purposes. Several fructo- and gluco-oligosaccharides are known to stimulate the growth of bifidobacteria in the human colon. Fructo-oligosaccharides produced by the fructosyltransferase described above are also part of the invention. Another way of producing fructo-oligosaccharides is by hydrolysis of the fructans described above. This hydrolysis can be performed by known hydrolysis methods such as enzymatic hydrolysis with enzymes such as levanase or inulinase or by acid hydrolysis. The fructo-oligosaccharides can also be produced in the presence of a fructosyltransferase according to the invention and an acceptor molecule such as lactose or maltose. The fructo-oligosaccharides to be produced according to the invention preferably contain at least 2, more preferably at least 3, up to about 20 anhydrofructose units, optionally in addition to one or more other (glucose, galactose, etc.) units. These fructo-oligosaccharides are useful as prebiotics, and can be administered to a mammal in need of improving the bacterial status of the colon.

[0023] The invention also concerns chemically modified fructans and fructo-oligosaccharides based on the fructans described above. Chemical modification can be achieved by oxidation, such as hypochlorite oxidation resulting in ring-opened 2,3-dicarboxy-anhydrofructose units (see e.g. EP-A-427349), periodate oxidation resulting in ring-opened 3,4-dialdehyde-anhydrofructose units (see e.g. WO 95/12619), which can be further oxidized to (partly) carboxylated units (see e.g. WO 00/26257), nitroxyl (TEMPO)-mediated oxidation resulting in 1-carboxy-anhydrofructose units (in levans) or 6-carboxy-anhydrofructose units (in inulins) (see e.g. WO 95/07303). The oxidized fructans have improved water-solubility, altered viscosity and a retarded fermentability and can be used as metal-complexing agents, detergent additives, strengthening additives, bioactive carbohydrates, emulsifiers and water binding agents. They can also be used as starting materials for further derivatisation such as cross-linking and the introduction of hydrophobes. Oxidized fructans coupled to amino compounds such as proteins, or fatty acids can be used as emulsifiers and stabilizers. (Partial) hydrolysis of fructans according to the invention and modified fructans according to the invention results in fructo-oligosaccharides, which can be used as bioactive carbohydrates or prebiotics. The oxidized fructans of the invention preferably contain 0.05-1.0 carboxyl groups per anhydrofructose unit, e.g. as 6- or 1-carboxyl units. For use as e.g. a water treatment chemical serving as an alternative for acrylate-based products (e.g. flocculant or anti-scaling) or paper additive (aldehyde-containing polymer) the preferred degree of oxidation (aldehyde or carboxyl content) is between 0.1 and 0.8 aldehyde/carboxyl groups per anhydrofructose unit and the preferred degree of polymerization is between 37 and 12,500 anhydrofructose units (molecular weight between about 6 and 2,000 kDa. Alternatively, negative charges can be introduced into the molecule by, e.g., carboxymethylation.

[0024] Another type of chemical modification is phosphorylation, as described in O. B. Wurzburg (1986) Modified Starches: properties and uses. CRC Press Inc., Boca Raton, 97-112. One way to achieve this modification is by dry heating fructans with a mixture of monosodium and disodium hydrogen phosphate or with tripolyphosphate. The phosphorylated fructans are suitable as wet-end additives in papermaking, as binders in paper coating compositions, as warp sizing-agents, and as core binders for sand molds for metal casting. A further type of derivatisation of the fructans is acylation, especially acetylation using acetic or propionic anhydride, resulting in products suitable as bleaching assistants and for the use in foils. Acylation with e.g. alkenyl succinic anhydrides or (activated) fatty acids results in surface-active products suitable as e.g. surfactants, emulsifiers, and stabilizers.

[0025] Hydroxyalkylation, carboxymethylation, epoxyalkylation and aminoalkylation are other methods of chemical derivatisation of the fructans. Hydroxyalkylation is commonly performed by base-catalysed reaction with alkylene oxides, such as ethylene oxide, propylene oxide or epichlorohydrine; the hydroxyalkylated products have improved solubility and viscosity characteristics. Carboxymethylation is achieved by reaction of the fructans with monochloroacetic acid or its alkali metal salts and results in anionic polymers suitable for various purposes including crystallisation inhibitors, and metal complexants. Epoxyalkylation can be achieved using diepoxy compounds such as diglycidyl ether and bis-epoxyalkanes, but is preferably performed by first reacting the fructan with an epoxyalkene such as 1,2-epoxy-5-hexene or allyl glycidyl ether followed by oxidation of the ethylenic bond to an epoxide using a peracid or hydrogen peroxide as described in WO 01/87986. The epoxyalkylated fructans can be used for coupling compounds having e.g. carboxyl, amino or mercapto groups, including peptides and proteins, for producing crosslinked fructans. Aminoalkylation can be achieved by reaction of the fructans with alkylene imines, haloalkyl amines or amino-alkylene oxides, or by reaction of epichlorohydrin adducts of the fructans with suitable amines. These products can be used as cationic polymers in a variety of applications, especially as a wet-end additive in paper making to increase strength, for filler and fines retention, and to improve the drainage rate of paper pulp. Other potential applications include textile sizing and waste water purification.

[0026] The above mentioned modifications can be used either separately or in combination depending on the desired product. Furthermore, the degree of chemical modification is variable and depends on the intended use. If necessary 100% modification, i.e. modification of all anhydrofructose units can be performed. However, partial modification, e.g. from 1 modified anhydrofructose unit per 100 up to higher levels, will often be sufficient in order to obtain the desired effect. The modified fructans have a DP (degree of polymerization) of at least 100, preferably at least 1000 units. Use of partially modified fructans containing, e.g., (negative) charges as well as aldehyde moieties are particularly useful in paper applications and textile treatment. These have a degree of substitution for aldehyde groups between 1 and 50%, preferably between 5 and 40%, and a degree of substitution for carboxyl or other charged groups between 1 and 50%, preferably between 5 and 40%.

[0027] Use of a Lactobacillus strain capable of producing a levan, inulin or fructo-oligosaccharides or a mixture thereof, as a probiotic, is also covered by the invention. Preferably, the Lactobacillus strain is also capable of producing a glucan, especially an 1,4/1,6-α-glucan as referred to above. The efficacy of some Lactobacillus reuteri strains as a probiotics has been demonstrated in various animals such as for instance poultry and humans. The administration of some Lactobacillus reuteri strains to pigs resulted in significantly lower serum total and LDL-cholesterol levels, while in children Lactobacillus reuteri is used as a therapeutic agent against acute diarrhea. For this and other reasons Lactobacillus reuteri strains, which were not reported to produce the glucans or fructans described herein, have been supplemented to commercially available probiotic products. The mode of action of Lactobacillus reuteri as a probiotic is still unclear. Preliminary studies indicated that gut colonization by Lactobacillus reuteri may be of importance. According to the invention, it was found that the mode of action of Lactobacillus reuteri as a probiotic may reside partly in the ability to produce polysaccharides. Lactobacillus strains, preferably Lactobacillus reuteri strains, and more preferably Lactobacillus reuteri strain LB 121 and other strains containing one or more fructosyltransferase genes encoding proteins capable of producing inulins, levans and/or fructo-oligosaccharides can thus advantageously be used as a probiotic. They can also, together with these polysaccharides, be used as a symbiotic (instead of the term symbiotic, the term synbiotic can also be used). In that respect another part of the invention concerns a probiotic or symbiotic composition containing a Lactobacillus strain capable of producing an inulin, a levan or fructo-oligosaccharides and/or a glucan or a mixture thereof, said production being performed according to the process according to the invention. The probiotic or symbiotic compositions of the invention may be directly ingested with or without a suitable vehicle or used as an additive in conjunction with foods. They can be incorporated into a variety of foods and beverages including, but not limited to, yogurts, ice creams, cheeses, baked products such as bread, biscuits and cakes, dairy and dairy substitute foods, confectionery products, edible oil compositions, spreads, breakfast cereals, juices and the like.

[0028] Furthermore, the invention pertains to a process of improving the microbial status in the mammalian colon comprising administering an effective amount of a Lactobacillus strain capable of producing an oligosaccharide or polysaccharide according ot the invention and to a process of improving the microbial status of the mammalian colon comprising administering an effective amount of an oligosaccharide or polysaccharide produced according to the process according to the invention.

EXAMPLES Example 1

[0029] Isolation of DNA from Lactobacillus reuteri, nucleotide sequence analysis of the inulosucrase (ftfA) gene, construction of plasmids for expression of the inulosucrase gene in E. coli Top10, expression of the inulosucrase gene in E. coli Top10 and identification of the produced polysaccharides produced by the recombinant enzyme. General procedures for cloning, DNA manipulations and agarose gel electrophoresis were essentially as described by Sambrook et al. (1989) Molecular cloning: a laboratory manual, 2nd ed. Cold Spring Harbour Laboratory Press, Cold Spring Harbour, N.Y. Restriction endonuclease digestions and ligations with T4 DNA ligase were performed as recommended by the suppliers. DNA was amplified by PCR techniques using ampliTAQ DNA polymerase (Perkin Elmer) or Pwo DNA polymerase. DNA fragments were isolated from agarose gels using the Qiagen extraction kit (Qiagen GMBH), following the instructions of the suppliers. Lactobacillus reuteri strain 121 (LMG 18388) was grown at 37° C. in MRS medium (DIFCO) or in MRS-s medium (MRS medium containing 100 g/l sucrose instead of 20 g/l glucose). When fructo-oligosaccharides production was investigated phosphate was omitted and ammonium citrate was replaced by ammonium nitrate in the MRS-s medium. E. coli strains were grown aerobically at 37° C. in LB medium, where appropriate supplemented with 50 μg/ml ampicillin (for selection of recombinant plasmids) or with 0.02% (w/v) arabinose (for induction of the inulosucrase gene).

[0030] Total DNA of Lactobacillus reuteri was isolated according to Verhasselt et al. (1989) FEMS Microbiol. Lett. 59, 135-140 as modified by Nagy et al. (1995) J. Bacteriol. 177, 676-687.

[0031] The inulosucrase gene was identified by amplification of chromosomal DNA of Lactobacillus reuteri with PCR using degenerated primers (5ftf, 6ftfi, and 12ftfi, see table 1) based on conserved amino acid sequences deduced from different bacterial fructosyltranferase genes (SacB of Bacillus amyloliquefaciens, SacB of Bacillus subtilis, Streptococcus mutans fructosyltransferase and Streptococcus salivarius fructosyltransferase, see FIG. 4) and Lactobacillus reuteri DNA as template. Using primers 5ftf and 6ftfi, an amplification product with the predicted size of about 234 bp was obtained (FIG. 5A). This 234 bp fragment was cloned in E. coli JM109 using the pCR2.1 vector and sequenced. Transformations were performed by electroporation using the BioRad gene pulser apparatus at 2.5 kV, 25 μF and 200 Ω, following the instructions of the manufacturer. Sequencing was performed according to the method of Sanger et al. (1977) Proc. Natl. Acad. Sci. USA 74, 5463-5467. Analysis of the obtained sequence data confirmed that part of a fructosyltransferase (ftf) gene had been isolated. The 234 bp amplified fragment was used to design primers 7ftf and 8ftfi (see table 1). PCR with the primers 7ftf and 12ftfi gave a product of the predicted size of 948 bp (see FIG. 5B); its sequence showed clear similarity with previously characterized fructosyltransferase genes. The 948 bp amplified fragment was used to design the primers ftfAC1(i) and ftfAC2(i) (see table 1) for inverse PCR. Using inverse PCR techniques a 1438 bp fragment of the inulosucrase gene was generated, including the 3′ end of the inulosucrase gene (see FIG. 5C). The remaining 5′ fragment of the inulosucrase gene was isolated with a combination of standard and inverse PCR techniques. Briefly, Lactobacillus reuteri DNA was cut with restriction enzyme XhoI and ligated. PCR with the primers 7ftf and 8ftfi, using the ligation product as a template, yielded a 290 bp PCR product which was cloned into pCR2.1 and sequenced. This revealed that primer 8ftfi had annealed aspecifically as well as specifically yielding the 290 bp product (see FIG. 5D).

[0032] At this time, the N-terminal amino acid sequence of a fructosyltransferase enzyme (FTFB) purified from the Lactobacillus reuteri strain 121 was obtained. This sequence consisted of the following 23 amino acids: QVESNNYNGVAEVNTERQANGQI (residues 2-24 of SEQ ID No. 6). The degenerated primer 19ftf (YNGVAEV) (residues 8-14 of SEQ ID No. 6) was designed on the basis of a part of this N-terminal peptide sequence and primer 20ftfi was designed on the 290 bp PCR product. PCR with primers 19ftf and 20ftfi gave a 754 bp PCR product (see FIG. 5E), which was cloned into pCR2.1 and sequenced. Both DNA strands of the entire fructosyltransferase gene were double sequenced. In this way the sequence of a 2.6 kb region of the Lactobacillus reuteri DNA, containing the inulosucrase gene and its surroundings were obtained.

[0033] The plasmids for expression of the inulosucrase gene in E. coli Top10 were constructed as described hereafter. A 2414 bp fragment, containing the inulosucrase gene starting at the first putative start codon at position 41, was generated by PCR, using primers ftfA1 and ftfA2i. Both primers contained suitable restriction enzyme recognition sites (a NcoI site at the 5′end of ftfA1 and a BglII site at the 3′end of ftfA2i). PCR with Lactobacillus reuteri DNA, Pwo DNA polymerase and primers ftfA1 and ftfA2i yielded the complete inulosucrase gene flanked by NcoI and BglII restriction sites. The PCR product with blunt ends was ligated directly into pCRbluntII-Topo. Using the NcoI and BglII restriction sites, the putative ftfA gene was cloned into the expression vector pBAD, downstream of the inducible arabinose promoter and in frame upstream of the Myc epitope and the His tag. The pBAD vector containing the inulosucrase gene (pSVH101) was transformed to E. coli Top10 and used to study inulosucrase expression. Correct construction of plasmid containing the complete inulosucrase gene was confirmed by restriction enzyme digestion analysis and by sequence analysis, showing an in frame cloning of the inulosucrase gene using the ribosomal binding site provided by the pBAD vector and the first putative start codon (at position 41) of inulosucrase (see FIG. 1).

[0034] Plasmid DNA of E. coli was isolated using the alkaline lysis method of Birnboim and Doly (1979) Nucleic Acids Res. 7, 1513-1523 or with a Qiagen plasmid kit following the instructions of the supplier. Cells of E. coli Top10 with pSVH101 were grown overnight in LB medium containing 0.02% (w/v) arabinose and were harvested by centrifugation. The pellet was washed with 25 mM sodium acetate buffer pH 5.4 and the suspension was centrifuged again. Pelleted cells were resuspended in 25 mM sodium acetate buffer pH 5.4. Cells were broken by sonication. Cell debris and intact cells were removed by centrifugation for 30 min at 4° C. at 10,000×g and the resulting cell free extract was used in the enzyme assays.

[0035] The fructosyltranferase activities were determined at 37° C. in reaction buffer (25 mM sodium acetate, pH 5.4, 1 mM CaCl₂, 100 g/l sucrose) by monitoring the release of glucose from sucrose, by detecting fructo-oligosaccharides or by determining the amount of fructan polymer produced using E. coli cell free extracts or Lactobacillus reuteri culture supernatant as enzyme source. Sucrose, glucose and fructose were determined enzymatically using commercially available kits.

[0036] Fructan production by Lactobacillus reuteri was studied with cells grown in MRS-s medium. Product formation was also studied with cell-free extracts of E. coli containing the novel inulosucrase incubated in reaction buffer (1 mg protein/10 ml buffer, incubated overnight at 37° C.). Fructans were collected by precipitation with ethanol. ¹H-NMR spectroscopy and methylation analysis were performed as described by van Geel-Schutten et al. (1999) Appl. Environ. Microbiol. 65, 3008-3014. The molecular weights of the fructans were determined by high performance size exclusion chromatography coupled on-line with a multi angle laser light scattering and a differential refractive index detector. Fructo-oligosaccharide synthesis was studied in Lactobacillus reuteri culture supernatants and in extracts of E. coli cells containing the novel inulosucrase incubated in reaction buffer (1 mg protein/10 ml buffer, incubated overnight at 37° C.). Glucose and fructose were determined enzymatically as described above and fructo-oligosaccharides produced were analyzed using a Dionex column. The incubation mixtures were centrifuged for 30 min at 10,000×g and diluted 1:5 in a 100% DMSO solution prior to injection on a Dionex column. A digest of inulin (DP1-20) was used as a standard. Separation of compounds was achieved with anion-exchange chromatography on a CarboPac Pa1 column (Dionex) coupled to a CarboPac PA1 guard column (Dionex). Using a Dionex GP50 pump the following gradient was generated: % eluent B is 5% (0 min); 35% (10 min); 45% (20 min); 65% (50 min); 100% (54-60 min); 5% (61-65 min). Eluent A was 0.1 M NaOH and eluent B was 0.6 M NaAc in a 0.1 M NaOH solution. Compounds were detected using a Dionex ED40 electrochemical detector with an AU working electrode and a Ag/AgCl reference-electrode with a sensitivity of 300 nC. The pulse program used was: +0.1 Volt (0-0.4 s); +0.7 Volt (0.41-0.60 s); −0.1 Volt (0.61-1.00 s). Data were integrated using a Perkin Elmer Turbochrom data integration system. A different separation of compounds was done on a cation exchange column in the calcium form (Benson BCX4). As mobile phase C a-EDTA in water (100 ppm) was used. The elution speed was 0.4 ml/min at a column temperature of 85° C. Detection of compounds was done by a refractive index (Jasco 830-RI) at 40° C. Quantification of compounds was achieved by using the software program Turbochrom (Perkin Elmer).

[0037] SDS-PAGE was performed according to Laemmli (1970) Nature 227, 680-685 using 7.5% polyacrylamide gels. After electrophoresis gels were stained with Coomassie Brilliant Blue or an activity staining (Periodic Acid Schiff, PAS) was carried out as described by Van Geel-Schutten et al. (1999) Appl. Environ. Microbiol. 65, 3008-3014. TABLE 1 Nucleotide sequence of primers used in PCR reactions to identify the inulosucrase gene. Primer Location Nucleotide sequence name (bp) (and SEQ ID No) ftfAC1 1176 CTG-ATA-ATA-ATG-GAA-ATG-TAT-CAC (SEQ ID No. 12) ftfAC2i 1243 CAT-GAT-CAT-AAG-TTT-GGT-AGT-AAT-AG (SEQ ID No. 13) ftfac1 1176 GTG-ATA-CAT-TTC-CAT-TAT-TAT-CAG (SEQ ID No. 14) ftfAC2 1243 CTA-TTA-CTA-CCA-AAC-TTA-TGA-TCA-TG (SEQ ID No. 15) ftfA1 CCA-TGG-CCA-TGG-TAG-AAC-GCA-AGG-AAC ATA-AAA-AAA-TG (SEQ ID No. 16) ftfA2i AGA-TCT-AGA-TCT-GTT-AAA-TCG-ACG-TTT- GTT-AAT-TTC-TG (SEQ ID No. 17) 5ftf 845 GAY-GTN-TGG-GAY-WSN-TGG-GCC (SEQ ID No. 18) 6ftfi 1052 GTN-GCN-SWN-CCN-SWC-CAY-TSY-TG (SEQ ID No. 19) 7ftf 1009 GAA-TGT-AGG-TCC-AAT-TTT-TGG-C (SEQ ID No. 20) 8ftfi 864 CCT-GTC-CGA-ACA-TCT-TGA-ACT-G (SEQ ID No. 21) 12ftfi 1934 ARR-AAN-SWN-GGN-GCV-MAN-GTN-SW (SEQ ID No. 22) 19ftf 1 TAY-AAY-GGN-GTN-GCN-GAR-GTN-AA (SEQ ID No. 23) 20ftfi 733 CCG-ACC-ATC-TTG-TTT-GAT-TAA-C (SEQ ID No. 24)

[0038] Listed from left to right are: primer name (i, inverse primer), location (in bp) in ftfA and the sequence from 5′ to 3′ according to IUB group codes (N=any base;M=A or C; R=A or G; W=A or T; S=C or G; Y=C or T; K=G or T; B=not A; D=not C; H=not G; and V=not T).

Example 2

[0039] Purification and amino acid sequencing of the levansucrase (FTFB).

[0040] Protein purification

[0041] Samples were taken between each step of the purification process to determine the enzyme activity (by glucose GOD-Perid method) and protein content (by Bradford analysis and acrylamide gel electrophoresis). Collected chromatography fractions were screened for glucose liberating activity (GOD-Perid method) to determine the enzyme activity.

[0042] One liter of an overnight culture of LB121 cells grown on MRS medium containing 50 grams per liter maltose was centrifuged for 15 min. at 10,000×g. The supernatant was precipitated with 1.5 liter of a saturated ammonium sulphate solution. The ammonium sulphate solution was added at a rate of 50 ml/min. under continuous stirring. The resulting 60% (w/v) ammonium sulphate solution was centrifuged for 15 min. at 10,000×g. The precipitate was resuspended in 10 ml of a sodium phosphate solution (10 mM, pH 6.0) and dialyzed overnight against 10 mM sodium phosphate, pH 6.0.

[0043] A hydroxylapatite column was washed with a 10 mM sodium phosphate solution pH 6.0; the dialyzed sample was loaded on the column. After eluting the column with 200 mM sodium phosphate, pH 6.0 the eluted fractions were screened for glucose releasing activity and fractions were pooled for phenyl superose (a hydrophobic interactions column) chromatography.

[0044] The pooled fractions were diluted 1:1 (v:v) with 25 mM sodium acetate, 2 M ammonium sulphate, pH 5.4 and loaded on a phenyl superose column (washed with 25 mM sodium acetate, 1 M ammonium sulphate, pH 5.4). In a gradient from 25 mM sodium acetate, 1 M ammonium sulphate, pH 5.4 (A) to 25 mM sodium acetate, pH 5.4 (B) fractions were collected from 35% B to 50% B.

[0045] Pooled fractions from the phenyl superose column were loaded on a gel filtration (superdex) column and eluted by a 25 mM acetate, 0.1 M sodium chloride, pH 5.4 buffer. The superdex fractions were loaded on a washed (with 25 mM sodium acetate, pH 5.4) Mono Q column and eluted with 25 mM sodium acetate, 1 M sodium chloride, pH 5.4. The fractions containing glucose liberating activity were pooled, dialyzed against 25 mM sodium acetate, pH 5.4, and stored at −20° C.

[0046] A levansucrase enzyme was purified from LB 121 cultures grown on media containing maltose using ammonium sulfate precipitation and several chromatography column steps (table 2). Maltose (glucose-glucose) was chosen because both glucansucrase and levansucrase can not use maltose as substrate. LB121 will grow on media containing maltose but will not produce polysaccharide. From earlier experiments it was clear that even with harsh methods the levansucrase enzyme could not be separated from its product levan. These harsh methods included boiling the levan in a SDS solution and treating the levan with HCl and TFA. No levanase enzyme was commercially available for the enzymatic breakdown of levan. Only a single levansucrase was detected in maltose culture supernatants. In order to prove that the enzyme purified from maltose culture supernatant is the same enzyme which is responsible for the levan production during growth on raffinose, biochemical and biophysical tests were performed. TABLE 2 Purification of the Lactobacillus reuteri LB 121 levansucrase (FTFB) enzyme. Total Specific Protein Activity Activity Purification Yield Step (mg) (U) (U/mg) (fold) (%) Supernatant 128 64 0.5 1 100 Ammonium sulfate 35.2 42 1.2 2.4 65.6 precipitation (65%) Hydroxyl apatite 1.5 30.6 20.4 40.8 47.8 Phenyl superose 0.27 23 85 170 36 Gel Filtration 0.055 10 182 360 16 MonoQ 0.0255 4 176 352 6

[0047] Amino acid sequencing of FTFB

[0048] A 5% SDS-PAA gel was allowed to “age” overnight in order to reduce the amount of reacting chemical groups in the gel. Reaction of chemicals in the PAA gel (TEMED and ammonium persulphate) with proteins can cause some undesired effects, such as N-terminal blocking of the protein, making it more difficult to determine the protein amino acid composition. 0.1 mM thioglycolic acid (scavenger to reduce the amount of reactive groups in the PAA gel material) was added to the running buffer during electrophoresis.

[0049] In order to determine the amino acid sequence of internal peptides of protein bands running in a SDS-PAA gel, protein containing bands were cut out of the PAA gel. After fractionating the protein by digestion with chymotrypsin the N-terminal amino acid sequences of the digested proteins were determined (below).

[0050] N-terminal sequencing was performed by Western blotting of the proteins from the PAA gel to an Immobilon PVDF membrane (Millipore/ Waters Inc.) at 0.8 mA/cm² for 1 h. After staining the PVDF membrane with Coomassie Brilliant Blue without adding acetic acid (to reduce N-terminal blocking) and destaining with 50% methanol, the corresponding bands were cut out of the PVDF membrane for N-terminal amino acid sequence determination.

[0051] Amino acid sequence determination was performed by automated Edman degradation as described by Koningsberg and Steinman (1977) The proteins (third edition) volume 3, 1-178 (Neurath and Hill, eds.). The automated equipment for Edman degradation was an Applied Biosystems model 477A pulse-liquid sequenator described by Hewick et al. (1981), J. Biol. Chem. 15, 7990-7997 connected to a RP-HPLC unit (model 120A, Applied Biosystems) for amino acid identification.

[0052] The N-terminal sequence of the purified FTFB was determined and found to be: (A) QVESNNYNGVAEVNTERQANGQI (G) (V) (D) (SEQ ID No.6). Three internal peptide sequences of the purified FTFB were determined: (M) (A) HLDV WDSWPVQDP (V) (SEQ ID No. 7); NAGSIFGT (K) (SEQ ID No. 8); and V (E) (E) VYSPKVSTLMASDEVE (SEQ ID No. 9).

[0053] The following primers were designed on the basis of the N-terminal and internal peptide fragments of FTFB. Listed from left to right are: primer name, source peptide fragment and sequence (from 5′ to 3′). FTFB1+FTFB3i yields approximately a 1400 bp product in a PCR reaction. FTFB1 forward (N-terminal): AA T/C-TAT-AA T/C-GG T/C-GTT-GC G/A-T/C GA-AGT (SEQ ID No. 25); and FTFB3i reverse (Internal 3): TAC-CGN-A/T C/G N-CTA-CTT-CAA-CTT (SEQ ID No. 26). The FTFB gene was partly isolated by PCR with primers FTFB1 and FTFB3i. PCR with these primers yielded a 1385 bp amplicon, which after sequencing showed high homology to ftfA and SacB from Streptococcus mutans.

Example 3

[0054] Oxidation of levans

[0055] For TEMPO-mediated oxidation, a levan according to the invention prepared as described above (dry weight 1 g, 6.15 mmol of monomeric units present, molar weight 10-1,000 kDa) was resuspended in 100 ml water. Next, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO; 1% by weight compared to the polysaccharide (0.01 g, 0.065 mmol)) was added and resuspended in 20 min. Sodium bromide (0.75 g, 7.3 mmol) was added and the suspension was cooled down to 0° C. This reaction also proceeded without bromide. A solution of hypochlorite (6 ml, 15% solution, 12.6 mmol) was adjusted to pH 10.0 with 3M HCl and cooled to 0C. This solution was added to the suspension of the polysaccharide and TEMPO. The course of the reaction was followed by monitoring the consumption of sodium hydroxide solution, which is equivalent to the formation of uronic acid. After 30 min, 60 ml 0.1M NaOH was consumed. This amount corresponds to the formation of 97% uronic acid. Thereafter, the solution was poured out in 96% ethanol (comprising 70% of the volume of the solution) causing the product to precipitate. The white precipitate was centrifuged, resuspended in ethanol/water (70/30 v/v) and centrifuged again. Next, the precipitate was resuspended in 96% ethanol and centrifuged. The obtained product was dried at reduced pressure. The uronic acid content was determined by means of the uronic acid assay according to Blumenkrantz and Abdoe-Hansen (Anal. Biochem., 54 (1973), 484). A calibration curve was generated using polygalacturonic acid (5, 10, 15 and 20 μg). With this calibration curve the uronic acid content in a sample of 20 μg of the product was determined. The obtained result was a content of 95% uronic acid with a yield of 96%.

[0056] Partial Oxidation

[0057] For partial oxidation, a levan according to the invention (dry weight 2 g, 12.3 mmol) was resuspended in 25 ml water. Next, TEMPO (1% by weight compared to the polysaccharide (0.02 g, 0.13 mmol)) was added, resuspended in 20 min and cooled to 0° C. A solution of hypochlorite (1 ml, 15% solution, 2.1 mmol) was adjusted to pH 9.0 with 3M HCl and cooled down to 0° C. This solution was added to the suspension of the polysaccharide and TEMPO. Within 5 min the mixture became a solid gel, due to the formation of aldehydes.

Example 4

[0058] Adhesion of Lactobacillus reuteri strains to Caco-2 cell lines

[0059] The adhesion of Lactobacillus reuteri strains to Caco-2 cell lines was determined as described below. Firstly, a bacterial suspension was prepared as follows. Lactobacillus reuteri strains LB 121, 35-5, K24 and DSM20016 and L. rhamnosus LGG (a well known probiotic strain with good adhering properties) were cultured in MRS broth supplemented with 5 μl/ml of methyl-1,2-[³H]-thymidine at 37° C. for 18-20 h before the adhesion assays. The cultures were harvested by centrifugation, washed with phosphate buffered saline (PBS) and resuspended in PBS or PBS supplemented with 30 g/l sucrose (see Table 3) to a final density of about 2×10⁹ cfu/ml. Prior to the adhesion assay, the cell suspensions in PBS with 30 g/l sucrose were incubated for 1 hour at 37° C., whereas the cell suspensions in PBS were kept on ice for 1 hour. After incubation at 37° C., the suspensions in PBS with sucrose were centrifuged and the cells were washed with and resuspended in PBS to a final density of about 2×10⁹ cfu/ml.

[0060] Caco-2 cells were cultured as follows. Subcultures of Caco-2 cells (ATCC, code HTB 37, human colon adenocarcinoma), stored as frozen stock cultures in liquid nitrogen were used for the adhesion tests. The Caco-2 cells were grown in culture medium consisting of Dulbecco's modified Eagle medium (DMEM), supplemented with heat-inactivated fetal calf serum (10% v/v), non-essential amino acids (1% v/v), L-glutamine (2 mM) and gentamycin (50 μg/ml). About 2,000,000 cells were seeded in 75 cm² tissue culture flasks containing culture medium and cultured in a humidified incubator at 37° C. in air containing 5% CO₂. Near confluent Caco-2 cell cultures were harvested by trypsinisation and resuspended in culture medium. The number of cells was established using a Bürker-Türk counting chamber. TABLE 3 Incubation of the different Lactobacillus strains prior to the adhesion assays. Lactobacillus Polysaccharide strain Extra incubation produced Group reuteri 121 PBS sucrose, 37° C. for glucan and fructan As 1 hr reuteri 35-5 PBS sucrose, 37° C. for glucan Bs 1 hr reuteri K24 PBS sucrose, 37° C. for none Cs 1 hr reuteri 121 PBS on ice none D reuteri PBS on ice none E DSM20016* rhamnosus GG PBS on ice none F

[0061] For the following experiments a Caco-2 monolayer transport system was used. Caco-2 cells cultured in a two-compartment transport system are commonly used to study the intestinal, epithelial permeability. In this system the Caco-2 cell differentiates into polarized columnar cells after reaching confluency. The Caco-2 system has been shown to simulate the passive and active transcellular tranport of electrolytes, sugars, amino acids and lipophilic compounds (Hillgren et al. 1995, Dulfer et al., 1996, Duizer et al., 1997). Also, a clear correlation between the in vivo absorption and the permeability across the monolayers of Caco-2 cells has been reported (Artursson and Karlsson, 1990). For the present transport studies, Caco-2 cells were seeded on semi-permeable filter inserts (12 wells Transwell plates, Costar) at ca. 100,000 cells per filter (growth area±1 cm² containing 2.5 ml culture medium). The cells on the insert were cultured for 17 to 24 days at 37° C. in a humidified incubator containing 5% CO₂ in air. During this culture period the cells have been subjected to an enterocyte-like differentiation. Gentamycin was eliminated from the culture medium two days prior to the adhesion assays.

[0062] The adhesion assay was performed as follows. PBS was used as exposure medium. 25 μl of a bacterial suspension (2×10⁹ cfu/ml ) were added to 0.5 ml medium. The apical side of the Caco-2 monolayers was incubated with the bacterial suspensions for 1 hour at 37° C. After incubation, remaining fluid was removed and the cells were washed three times with 1 ml PBS. Subsequently, the Caco-2 monolayers were digested overnight with 1 ml 0.1M NaOH, 1% SDS. The lysate was mixed with 10 ml Hionic Fluor scintillation liquid and the radioactivity was measured by liquid scintillation counting using a LKB/Wallac scintillation counter. As a control, the radioactivity of the bacterial suspensions was measured. For each test group, the percentage of bacteria attached to the monolayers was calculated. All adhesion tests were performed in quadruple. In Table 4 the results of the bacterial adhesion test to Caco-2 cell lines are given. From the results can be concluded that the glucans and the fructans contribute to the adherence of Lactobacillus reuteri to Caco-2 cellines. This could indicate that Lactobacillus reuteri strains producing EPS possess improved probiotic characteristics or that Lactobacillus reuteri and its polysaccharides could function as an excellent symbiotic. TABLE 4 The results of the bacterial adhesion test to Caco-2 cell lines. Group % of bacteria (see Table bound to the 1) monolayer As 6.5 Bs 5.7 Cs 1.8 D 2.3 E 0.9 F 1.3

DESCRIPTION OF THE FIGURES

[0063]FIG. 1: SEQ ID No. 1; The deduced amino acid sequence of the novel inulosucrase of Lactobacillus reuteri (amino acid 1-789). The nucleic acid (SEQ ID NO: 4) and deduced amino acid sequence (SEQ ID NOs: 27 and 1) of the novel inulosucrase of Lactobacillus reuteri. Also encompassed within the figure is the comparison peptide (SEQ ID NO: 28). Furthermore, the designations and orientation (<for 3′ to 5′ and >for 5′ to 3′) of the primers and the restriction enzymes used for (inverse) PCR, are shown at the right hand side. Putative start codons (ATG, at positions 41 and 68) and stop codon (TAA, at position 2435) are shown in bold. The positions of the primers used for PCR are shown in bold/underlined. The NheI restriction sites (at positions 1154 and 2592) used for inverse PCR are underlined. The primers used and their exact positions in the inulosucrase sequence are shown in table 1. Starting at amino acid 690, the 20 PXX (residues 690-749 of SEQ IN NO: 1) repeats are underlined. At amino acid 755 the LPXTG (SEQ ID NO: 5) motif is underlined.

[0064]FIG. 2: Dendrogram of bacterial and plant fructosyltransferases. The horizontal distances are a measure for the difference at the amino acid sequence level. 10% difference is indicated by the upper bar. Bootstrap values (in percentages) are given at the root of each tree. Fructosyltransferases of Gram positive bacteria are indicated in the lower half of the figure (B. staerothermophilus SurB; B. amyloliquefaciens SacB; B. subtilis SacB; S. mutans SacB; L. reuteri FtfA (inulosucrase); S. salivarius Ftf). Plant fructosyltransferases are indicated in the middle part of the figure (Cynara scolymus Ss-1ft; Allium cepa F-6gft; Hordeum vulgare Sf-6ft). Fructosyltransferases of Gram negative bacteria are shown in the upper part of the figure (Z. mobilis LevU; Z. mobilis SucE2; Z. mobilis SacB; E. amylovora Lcs; A. diazotrophicus LsdA).

[0065]FIG. 3: SEQ ID No. 2; The N-terminal (SEQ ID NO: 6) and three internal amino acid sequences (SEQ ID NOs: 7-9) of the novel levansucrase of Lactobacillus reuteri.

[0066]FIG. 4: Parts of an alignment of the deduced amino acid sequences of some bacterial fructosyltransferase genes (SEQ ID NOs: 29-40). Sequences in bold indicate the consensus sequences used to construct the degenerated primers 5ftf, 6ftfi and 12 ftfi. (*) indicates a position with a fully conserved amino acid residue. (:) indicates a position with a fully conserved ‘strong’ group: STA, NEQK, NHQK, NDEQ, QHRK, MILV, MILF, HY, FYW. (.) indicates a position with a fully conserved ‘weaker’ group: CSA, ATV, SAG, STNK, STPA, SGND, SNDEQK, NDEQHK, NEQHRK, FVLIM, HFY. Groups are according to the Pam250 residue weight matrix described by Altschul et al. (1990) J. Mol. Biol. 215, 403-410.

[0067]FIG. 5: The strategy used for the isolation of the inulosucrase gene from Lactobacillus reuteri 121 chromosomal DNA.

1 40 1 789 PRT Lactobacillus reuteri 1 Met Tyr Lys Ser Gly Lys Asn Trp Ala Val Val Thr Leu Ser Thr Ala 1 5 10 15 Ala Leu Val Phe Gly Ala Thr Thr Val Asn Ala Ser Ala Asp Thr Asn 20 25 30 Ile Glu Asn Asn Asp Ser Ser Thr Val Gln Val Thr Thr Gly Asp Asn 35 40 45 Asp Ile Ala Val Lys Ser Val Thr Leu Gly Ser Gly Gln Val Ser Ala 50 55 60 Ala Ser Asp Thr Thr Ile Arg Thr Ser Ala Asn Ala Asn Ser Ala Ser 65 70 75 80 Ser Ala Ala Asn Thr Gln Asn Ser Asn Ser Gln Val Ala Ser Ser Ala 85 90 95 Ala Ile Thr Ser Ser Thr Ser Ser Ala Ala Ser Leu Asn Asn Thr Asp 100 105 110 Ser Lys Ala Ala Gln Glu Asn Thr Asn Thr Ala Lys Asn Asp Asp Thr 115 120 125 Gln Lys Ala Ala Pro Ala Asn Glu Ser Ser Glu Ala Lys Asn Glu Pro 130 135 140 Ala Val Asn Val Asn Asp Ser Ser Ala Ala Lys Asn Asp Asp Gln Gln 145 150 155 160 Ser Ser Lys Lys Asn Thr Thr Ala Lys Leu Asn Lys Asp Ala Glu Asn 165 170 175 Val Val Lys Lys Ala Gly Ile Asp Pro Asn Ser Leu Thr Asp Asp Gln 180 185 190 Ile Lys Ala Leu Asn Lys Met Asn Phe Ser Lys Ala Ala Lys Ser Gly 195 200 205 Thr Gln Met Thr Tyr Asn Asp Phe Gln Lys Ile Ala Asp Thr Leu Ile 210 215 220 Lys Gln Asp Gly Arg Tyr Thr Val Pro Phe Phe Lys Ala Ser Glu Ile 225 230 235 240 Lys Asn Met Pro Ala Ala Thr Thr Lys Asp Ala Gln Thr Asn Thr Ile 245 250 255 Glu Pro Leu Asp Val Trp Asp Ser Trp Pro Val Gln Asp Val Arg Thr 260 265 270 Gly Gln Val Ala Asn Trp Asn Gly Tyr Gln Leu Val Ile Ala Met Met 275 280 285 Gly Ile Pro Asn Gln Asn Asp Asn His Ile Tyr Leu Leu Tyr Asn Lys 290 295 300 Tyr Gly Asp Asn Glu Leu Ser His Trp Lys Asn Val Gly Pro Ile Phe 305 310 315 320 Gly Tyr Asn Ser Thr Ala Val Ser Gln Glu Trp Ser Gly Ser Ala Val 325 330 335 Leu Asn Ser Asp Asn Ser Ile Gln Leu Phe Tyr Thr Arg Val Asp Thr 340 345 350 Ser Asp Asn Asn Thr Asn His Gln Lys Ile Ala Ser Ala Thr Leu Tyr 355 360 365 Leu Thr Asp Asn Asn Gly Asn Val Ser Leu Ala Gln Val Arg Asn Asp 370 375 380 Tyr Ile Val Phe Glu Gly Asp Gly Tyr Tyr Tyr Gln Thr Tyr Asp Gln 385 390 395 400 Trp Lys Ala Thr Asn Lys Gly Ala Asp Asn Ile Ala Met Arg Asp Ala 405 410 415 His Val Ile Glu Asp Gly Asn Gly Asp Arg Tyr Leu Val Phe Glu Ala 420 425 430 Ser Thr Gly Leu Glu Asn Tyr Gln Gly Glu Asp Gln Ile Tyr Asn Trp 435 440 445 Leu Asn Tyr Gly Gly Asp Asp Ala Phe Asn Ile Lys Ser Leu Phe Arg 450 455 460 Ile Leu Ser Asn Asp Asp Ile Lys Ser Arg Ala Thr Trp Ala Asn Ala 465 470 475 480 Ala Ile Gly Ile Leu Lys Leu Asn Lys Asp Glu Lys Asn Pro Lys Val 485 490 495 Ala Glu Leu Tyr Ser Pro Leu Ile Ser Ala Pro Met Val Ser Asp Glu 500 505 510 Ile Glu Arg Pro Asn Val Val Lys Leu Gly Asn Lys Tyr Tyr Leu Phe 515 520 525 Ala Ala Thr Arg Leu Asn Arg Gly Ser Asn Asp Asp Ala Trp Met Asn 530 535 540 Ala Asn Tyr Ala Val Gly Asp Asn Val Ala Met Val Gly Tyr Val Ala 545 550 555 560 Asp Ser Leu Thr Gly Ser Tyr Lys Pro Leu Asn Asp Ser Gly Val Val 565 570 575 Leu Thr Ala Ser Val Pro Ala Asn Trp Arg Thr Ala Thr Tyr Ser Tyr 580 585 590 Tyr Ala Val Pro Val Ala Gly Lys Asp Asp Gln Val Leu Val Thr Ser 595 600 605 Tyr Met Thr Asn Arg Asn Gly Val Ala Gly Lys Gly Met Asp Ser Thr 610 615 620 Trp Ala Pro Ser Phe Leu Leu Gln Ile Asn Pro Asp Asn Thr Thr Thr 625 630 635 640 Val Leu Ala Lys Met Thr Asn Gln Gly Asp Trp Ile Trp Asp Asp Ser 645 650 655 Ser Glu Asn Leu Asp Met Ile Gly Asp Leu Asp Ser Ala Ala Leu Pro 660 665 670 Gly Glu Arg Asp Lys Pro Val Asp Trp Asp Leu Ile Gly Tyr Gly Leu 675 680 685 Lys Pro His Asp Pro Ala Thr Pro Asn Asp Pro Glu Thr Pro Thr Thr 690 695 700 Pro Glu Thr Pro Glu Thr Pro Asn Thr Pro Lys Thr Pro Lys Thr Pro 705 710 715 720 Glu Asn Pro Gly Thr Pro Gln Thr Pro Asn Thr Pro Asn Thr Pro Glu 725 730 735 Ile Pro Leu Thr Pro Glu Thr Pro Lys Gln Pro Glu Thr Gln Thr Asn 740 745 750 Asn Arg Leu Pro Gln Thr Gly Asn Asn Ala Asn Lys Ala Met Ile Gly 755 760 765 Leu Gly Met Gly Thr Leu Leu Ser Met Phe Gly Leu Ala Glu Ile Asn 770 775 780 Lys Arg Arg Phe Asn 785 2 2367 DNA Lactobacillus reuteri 2 atgtataaaa gcggtaaaaa ttgggcagtc gttacactct cgactgctgc gctggtattt 60 ggtgcaacaa ctgtaaatgc atccgcggac acaaatattg aaaacaatga ttcttctact 120 gtacaagtta caacaggtga taatgatatt gctgttaaaa gtgtgacact tggtagtggt 180 caagttagtg cagctagtga tacgactatt agaacttctg ctaatgcaaa tagtgcttct 240 tctgccgcta atacacaaaa ttctaacagt caagtagcaa gttctgctgc aataacatca 300 tctacaagtt ccgcagcttc attaaataac acagatagta aagcggctca agaaaatact 360 aatacagcca aaaatgatga cacgcaaaaa gctgcaccag ctaacgaatc ttctgaagct 420 aaaaatgaac cagctgtaaa cgttaatgat tcttcagctg caaaaaatga tgatcaacaa 480 tccagtaaaa agaatactac cgctaagtta aacaaggatg ctgaaaacgt tgtaaaaaag 540 gcgggaattg atcctaacag tttaactgat gaccagatta aagcattaaa taagatgaac 600 ttctcgaaag ctgcaaagtc tggtacacaa atgacttata atgatttcca aaagattgct 660 gatacgttaa tcaaacaaga tggtcggtac acagttccat tctttaaagc aagtgaaatc 720 aaaaatatgc ctgccgctac aactaaagat gcacaaacta atactattga acctttagat 780 gtatgggatt catggccagt tcaagatgtt cggacaggac aagttgctaa ttggaatggc 840 tatcaacttg tcatcgcaat gatgggaatt ccaaaccaaa atgataatca tatctatctc 900 ttatataata agtatggtga taatgaatta agtcattgga agaatgtagg tccaattttt 960 ggctataatt ctaccgcggt ttcacaagaa tggtcaggat cagctgtttt gaacagtgat 1020 aactctatcc aattatttta tacaagggta gacacgtctg ataacaatac caatcatcaa 1080 aaaattgcta gcgctactct ttatttaact gataataatg gaaatgtatc actcgctcag 1140 gtacgaaatg actatattgt atttgaaggt gatggctatt actaccaaac ttatgatcaa 1200 tggaaagcta ctaacaaagg tgccgataat attgcaatgc gtgatgctca tgtaattgaa 1260 gatggtaatg gtgatcggta ccttgttttt gaagcaagta ctggtttgga aaattatcaa 1320 ggcgaggacc aaatttataa ctggttaaat tatggcggag atgacgcatt taatatcaag 1380 agcttattta gaattctttc caatgatgat attaagagtc gggcaacttg ggctaatgca 1440 gctatcggta tcctcaaact aaataaggac gaaaagaatc ctaaggtggc agagttatac 1500 tcaccattaa tttctgcacc aatggtaagc gatgaaattg agcgaccaaa tgtagttaaa 1560 ttaggtaata aatattactt atttgccgct acccgtttaa atcgaggaag taatgatgat 1620 gcttggatga atgctaatta tgccgttggt gataatgttg caatggtcgg atatgttgct 1680 gatagtctaa ctggatctta taagccatta aatgattctg gagtagtctt gactgcttct 1740 gttcctgcaa actggcggac agcaacttat tcatattatg ctgtccccgt tgccggaaaa 1800 gatgaccaag tattagttac ttcatatatg actaatagaa atggagtagc gggtaaagga 1860 atggattcaa cttgggcacc gagtttctta ctacaaatta acccggataa cacaactact 1920 gttttagcta aaatgactaa tcaaggggat tggatttggg atgattcaag cgaaaatctt 1980 gatatgattg gtgatttaga ctccgctgct ttacctggcg aacgtgataa acctgttgat 2040 tgggacttaa ttggttatgg attaaaaccg catgatcctg ctacaccaaa tgatcctgaa 2100 acgccaacta caccagaaac ccctgagaca cctaatactc ccaaaacacc aaagactcct 2160 gaaaatcctg ggacacctca aactcctaat acacctaata ctccggaaat tcctttaact 2220 ccagaaacgc ctaagcaacc tgaaacccaa actaataatc gtttgccaca aactggaaat 2280 aatgccaata aagccatgat tggcctaggt atgggaacat tgcttagtat gtttggtctt 2340 gcagaaatta acaaacgtcg atttaac 2367 3 2394 DNA Lactobacillus reuteri 3 atgctagaac gcaaggaaca taaaaaaatg tataaaagcg gtaaaaattg ggcagtcgtt 60 acactctcga ctgctgcgct ggtatttggt gcaacaactg taaatgcatc cgcggacaca 120 aatattgaaa acaatgattc ttctactgta caagttacaa caggtgataa tgatattgct 180 gttaaaagtg tgacacttgg tagtggtcaa gttagtgcag ctagtgatac gactattaga 240 acttctgcta atgcaaatag tgcttcttct gccgctaata cacaaaattc taacagtcaa 300 gtagcaagtt ctgctgcaat aacatcatct acaagttccg cagcttcatt aaataacaca 360 gatagtaaag cggctcaaga aaatactaat acagccaaaa atgatgacac gcaaaaagct 420 gcaccagcta acgaatcttc tgaagctaaa aatgaaccag ctgtaaacgt taatgattct 480 tcagctgcaa aaaatgatga tcaacaatcc agtaaaaaga atactaccgc taagttaaac 540 aaggatgctg aaaacgttgt aaaaaaggcg ggaattgatc ctaacagttt aactgatgac 600 cagattaaag cattaaataa gatgaacttc tcgaaagctg caaagtctgg tacacaaatg 660 acttataatg atttccaaaa gattgctgat acgttaatca aacaagatgg tcggtacaca 720 gttccattct ttaaagcaag tgaaatcaaa aatatgcctg ccgctacaac taaagatgca 780 caaactaata ctattgaacc tttagatgta tgggattcat ggccagttca agatgttcgg 840 acaggacaag ttgctaattg gaatggctat caacttgtca tcgcaatgat gggaattcca 900 aaccaaaatg ataatcatat ctatctctta tataataagt atggtgataa tgaattaagt 960 cattggaaga atgtaggtcc aatttttggc tataattcta ccgcggtttc acaagaatgg 1020 tcaggatcag ctgttttgaa cagtgataac tctatccaat tattttatac aagggtagac 1080 acgtctgata acaataccaa tcatcaaaaa attgctagcg ctactcttta tttaactgat 1140 aataatggaa atgtatcact cgctcaggta cgaaatgact atattgtatt tgaaggtgat 1200 ggctattact accaaactta tgatcaatgg aaagctacta acaaaggtgc cgataatatt 1260 gcaatgcgtg atgctcatgt aattgaagat ggtaatggtg atcggtacct tgtttttgaa 1320 gcaagtactg gtttggaaaa ttatcaaggc gaggaccaaa tttataactg gttaaattat 1380 ggcggagatg acgcatttaa tatcaagagc ttatttagaa ttctttccaa tgatgatatt 1440 aagagtcggg caacttgggc taatgcagct atcggtatcc tcaaactaaa taaggacgaa 1500 aagaatccta aggtggcaga gttatactca ccattaattt ctgcaccaat ggtaagcgat 1560 gaaattgagc gaccaaatgt agttaaatta ggtaataaat attacttatt tgccgctacc 1620 cgtttaaatc gaggaagtaa tgatgatgct tggatgaatg ctaattatgc cgttggtgat 1680 aatgttgcaa tggtcggata tgttgctgat agtctaactg gatcttataa gccattaaat 1740 gattctggag tagtcttgac tgcttctgtt cctgcaaact ggcggacagc aacttattca 1800 tattatgctg tccccgttgc cggaaaagat gaccaagtat tagttacttc atatatgact 1860 aatagaaatg gagtagcggg taaaggaatg gattcaactt gggcaccgag tttcttacta 1920 caaattaacc cggataacac aactactgtt ttagctaaaa tgactaatca aggggattgg 1980 atttgggatg attcaagcga aaatcttgat atgattggtg atttagactc cgctgcttta 2040 cctggcgaac gtgataaacc tgttgattgg gacttaattg gttatggatt aaaaccgcat 2100 gatcctgcta caccaaatga tcctgaaacg ccaactacac cagaaacccc tgagacacct 2160 aatactccca aaacaccaaa gactcctgaa aatcctggga cacctcaaac tcctaataca 2220 cctaatactc cggaaattcc tttaactcca gaaacgccta agcaacctga aacccaaact 2280 aataatcgtt tgccacaaac tggaaataat gccaataaag ccatgattgg cctaggtatg 2340 ggaacattgc ttagtatgtt tggtcttgca gaaattaaca aacgtcgatt taac 2394 4 2592 DNA Lactobacillus reuteri CDS (1)..(51) CDS (68)..(2434) 4 tac aat ggg gtg gcg gag gtg aag aaa cgg ggt tac ttc tat gct aga 48 Tyr Asn Gly Val Ala Glu Val Lys Lys Arg Gly Tyr Phe Tyr Ala Arg 1 5 10 15 acg caaggaacat aaaaaa atg tat aaa agc ggt aaa aat tgg gca gtc gtt 100 Thr Met Tyr Lys Ser Gly Lys Asn Trp Ala Val Val 20 25 aca ctc tcg act gct gcg ctg gta ttt ggt gca aca act gta aat gca 148 Thr Leu Ser Thr Ala Ala Leu Val Phe Gly Ala Thr Thr Val Asn Ala 30 35 40 tcc gcg gac aca aat att gaa aac aat gat tct tct act gta caa gtt 196 Ser Ala Asp Thr Asn Ile Glu Asn Asn Asp Ser Ser Thr Val Gln Val 45 50 55 60 aca aca ggt gat aat gat att gct gtt aaa agt gtg aca ctt ggt agt 244 Thr Thr Gly Asp Asn Asp Ile Ala Val Lys Ser Val Thr Leu Gly Ser 65 70 75 ggt caa gtt agt gca gct agt gat acg act att aga act tct gct aat 292 Gly Gln Val Ser Ala Ala Ser Asp Thr Thr Ile Arg Thr Ser Ala Asn 80 85 90 gca aat agt gct tct tct gcc gct aat aca caa aat tct aac agt caa 340 Ala Asn Ser Ala Ser Ser Ala Ala Asn Thr Gln Asn Ser Asn Ser Gln 95 100 105 gta gca agt tct gct gca ata aca tca tct aca agt tcc gca gct tca 388 Val Ala Ser Ser Ala Ala Ile Thr Ser Ser Thr Ser Ser Ala Ala Ser 110 115 120 tta aat aac aca gat agt aaa gcg gct caa gaa aat act aat aca gcc 436 Leu Asn Asn Thr Asp Ser Lys Ala Ala Gln Glu Asn Thr Asn Thr Ala 125 130 135 140 aaa aat gat gac acg caa aaa gct gca cca gct aac gaa tct tct gaa 484 Lys Asn Asp Asp Thr Gln Lys Ala Ala Pro Ala Asn Glu Ser Ser Glu 145 150 155 gct aaa aat gaa cca gct gta aac gtt aat gat tct tca gct gca aaa 532 Ala Lys Asn Glu Pro Ala Val Asn Val Asn Asp Ser Ser Ala Ala Lys 160 165 170 aat gat gat caa caa tcc agt aaa aag aat act acc gct aag tta aac 580 Asn Asp Asp Gln Gln Ser Ser Lys Lys Asn Thr Thr Ala Lys Leu Asn 175 180 185 aag gat gct gaa aac gtt gta aaa aag gcg gga att gat cct aac agt 628 Lys Asp Ala Glu Asn Val Val Lys Lys Ala Gly Ile Asp Pro Asn Ser 190 195 200 tta act gat gac cag att aaa gca tta aat aag atg aac ttc tcg aaa 676 Leu Thr Asp Asp Gln Ile Lys Ala Leu Asn Lys Met Asn Phe Ser Lys 205 210 215 220 gct gca aag tct ggt aca caa atg act tat aat gat ttc caa aag att 724 Ala Ala Lys Ser Gly Thr Gln Met Thr Tyr Asn Asp Phe Gln Lys Ile 225 230 235 gct gat acg tta atc aaa caa gat ggt cgg tac aca gtt cca ttc ttt 772 Ala Asp Thr Leu Ile Lys Gln Asp Gly Arg Tyr Thr Val Pro Phe Phe 240 245 250 aaa gca agt gaa atc aaa aat atg cct gcc gct aca act aaa gat gca 820 Lys Ala Ser Glu Ile Lys Asn Met Pro Ala Ala Thr Thr Lys Asp Ala 255 260 265 caa act aat act att gaa cct tta gat gta tgg gat tca tgg cca gtt 868 Gln Thr Asn Thr Ile Glu Pro Leu Asp Val Trp Asp Ser Trp Pro Val 270 275 280 caa gat gtt cgg aca gga caa gtt gct aat tgg aat ggc tat caa ctt 916 Gln Asp Val Arg Thr Gly Gln Val Ala Asn Trp Asn Gly Tyr Gln Leu 285 290 295 300 gtc atc gca atg atg gga att cca aac caa aat gat aat cat atc tat 964 Val Ile Ala Met Met Gly Ile Pro Asn Gln Asn Asp Asn His Ile Tyr 305 310 315 ctc tta tat aat aag tat ggt gat aat gaa tta agt cat tgg aag aat 1012 Leu Leu Tyr Asn Lys Tyr Gly Asp Asn Glu Leu Ser His Trp Lys Asn 320 325 330 gta ggt cca att ttt ggc tat aat tct acc gcg gtt tca caa gaa tgg 1060 Val Gly Pro Ile Phe Gly Tyr Asn Ser Thr Ala Val Ser Gln Glu Trp 335 340 345 tca gga tca gct gtt ttg aac agt gat aac tct atc caa tta ttt tat 1108 Ser Gly Ser Ala Val Leu Asn Ser Asp Asn Ser Ile Gln Leu Phe Tyr 350 355 360 aca agg gta gac acg tct gat aac aat acc aat cat caa aaa att gct 1156 Thr Arg Val Asp Thr Ser Asp Asn Asn Thr Asn His Gln Lys Ile Ala 365 370 375 380 agc gct act ctt tat tta act gat aat aat gga aat gta tca ctc gct 1204 Ser Ala Thr Leu Tyr Leu Thr Asp Asn Asn Gly Asn Val Ser Leu Ala 385 390 395 cag gta cga aat gac tat att gta ttt gaa ggt gat ggc tat tac tac 1252 Gln Val Arg Asn Asp Tyr Ile Val Phe Glu Gly Asp Gly Tyr Tyr Tyr 400 405 410 caa act tat gat caa tgg aaa gct act aac aaa ggt gcc gat aat att 1300 Gln Thr Tyr Asp Gln Trp Lys Ala Thr Asn Lys Gly Ala Asp Asn Ile 415 420 425 gca atg cgt gat gct cat gta att gaa gat ggt aat ggt gat cgg tac 1348 Ala Met Arg Asp Ala His Val Ile Glu Asp Gly Asn Gly Asp Arg Tyr 430 435 440 ctt gtt ttt gaa gca agt act ggt ttg gaa aat tat caa ggc gag gac 1396 Leu Val Phe Glu Ala Ser Thr Gly Leu Glu Asn Tyr Gln Gly Glu Asp 445 450 455 460 caa att tat aac tgg tta aat tat ggc gga gat gac gca ttt aat atc 1444 Gln Ile Tyr Asn Trp Leu Asn Tyr Gly Gly Asp Asp Ala Phe Asn Ile 465 470 475 aag agc tta ttt aga att ctt tcc aat gat gat att aag agt cgg gca 1492 Lys Ser Leu Phe Arg Ile Leu Ser Asn Asp Asp Ile Lys Ser Arg Ala 480 485 490 act tgg gct aat gca gct atc ggt atc ctc aaa cta aat aag gac gaa 1540 Thr Trp Ala Asn Ala Ala Ile Gly Ile Leu Lys Leu Asn Lys Asp Glu 495 500 505 aag aat cct aag gtg gca gag tta tac tca cca tta att tct gca cca 1588 Lys Asn Pro Lys Val Ala Glu Leu Tyr Ser Pro Leu Ile Ser Ala Pro 510 515 520 atg gta agc gat gaa att gag cga cca aat gta gtt aaa tta ggt aat 1636 Met Val Ser Asp Glu Ile Glu Arg Pro Asn Val Val Lys Leu Gly Asn 525 530 535 540 aaa tat tac tta ttt gcc gct acc cgt tta aat cga gga agt aat gat 1684 Lys Tyr Tyr Leu Phe Ala Ala Thr Arg Leu Asn Arg Gly Ser Asn Asp 545 550 555 gat gct tgg atg aat gct aat tat gcc gtt ggt gat aat gtt gca atg 1732 Asp Ala Trp Met Asn Ala Asn Tyr Ala Val Gly Asp Asn Val Ala Met 560 565 570 gtc gga tat gtt gct gat agt cta act gga tct tat aag cca tta aat 1780 Val Gly Tyr Val Ala Asp Ser Leu Thr Gly Ser Tyr Lys Pro Leu Asn 575 580 585 gat tct gga gta gtc ttg act gct tct gtt cct gca aac tgg cgg aca 1828 Asp Ser Gly Val Val Leu Thr Ala Ser Val Pro Ala Asn Trp Arg Thr 590 595 600 gca act tat tca tat tat gct gtc ccc gtt gcc gga aaa gat gac caa 1876 Ala Thr Tyr Ser Tyr Tyr Ala Val Pro Val Ala Gly Lys Asp Asp Gln 605 610 615 620 gta tta gtt act tca tat atg act aat aga aat gga gta gcg ggt aaa 1924 Val Leu Val Thr Ser Tyr Met Thr Asn Arg Asn Gly Val Ala Gly Lys 625 630 635 gga atg gat tca act tgg gca ccg agt ttc tta cta caa att aac ccg 1972 Gly Met Asp Ser Thr Trp Ala Pro Ser Phe Leu Leu Gln Ile Asn Pro 640 645 650 gat aac aca act act gtt tta gct aaa atg act aat caa ggg gat tgg 2020 Asp Asn Thr Thr Thr Val Leu Ala Lys Met Thr Asn Gln Gly Asp Trp 655 660 665 att tgg gat gat tca agc gaa aat ctt gat atg att ggt gat tta gac 2068 Ile Trp Asp Asp Ser Ser Glu Asn Leu Asp Met Ile Gly Asp Leu Asp 670 675 680 tcc gct gct tta cct ggc gaa cgt gat aaa cct gtt gat tgg gac tta 2116 Ser Ala Ala Leu Pro Gly Glu Arg Asp Lys Pro Val Asp Trp Asp Leu 685 690 695 700 att ggt tat gga tta aaa ccg cat gat cct gct aca cca aat gat cct 2164 Ile Gly Tyr Gly Leu Lys Pro His Asp Pro Ala Thr Pro Asn Asp Pro 705 710 715 gaa acg cca act aca cca gaa acc cct gag aca cct aat act ccc aaa 2212 Glu Thr Pro Thr Thr Pro Glu Thr Pro Glu Thr Pro Asn Thr Pro Lys 720 725 730 aca cca aag act cct gaa aat cct ggg aca cct caa act cct aat aca 2260 Thr Pro Lys Thr Pro Glu Asn Pro Gly Thr Pro Gln Thr Pro Asn Thr 735 740 745 cct aat act ccg gaa att cct tta act cca gaa acg cct aag caa cct 2308 Pro Asn Thr Pro Glu Ile Pro Leu Thr Pro Glu Thr Pro Lys Gln Pro 750 755 760 gaa acc caa act aat aat cgt ttg cca caa act gga aat aat gcc aat 2356 Glu Thr Gln Thr Asn Asn Arg Leu Pro Gln Thr Gly Asn Asn Ala Asn 765 770 775 780 aaa gcc atg att ggc cta ggt atg gga aca ttg ctt agt atg ttt ggt 2404 Lys Ala Met Ile Gly Leu Gly Met Gly Thr Leu Leu Ser Met Phe Gly 785 790 795 ctt gca gaa att aac aaa cgt cga ttt aac taaatacttt aaaataaaac 2454 Leu Ala Glu Ile Asn Lys Arg Arg Phe Asn 800 805 cgctaagcct taaattcagc ttaacggttt tttattttaa aagtttttat tgtaaaaaag 2514 cgaattatca ttaatactaa tgcaattgtt gtaagacctt acgacagtag taacaatgaa 2574 tttgcccatc tttgtcgg 2592 5 5 PRT Lactobacillus reuteri MOD_RES (3) Any amino acid 5 Leu Pro Xaa Thr Gly 1 5 6 27 PRT Lactobacillus reuteri 6 Ala Gln Val Glu Ser Asn Asn Tyr Asn Gly Val Ala Glu Val Asn Thr 1 5 10 15 Glu Arg Gln Ala Asn Gly Gln Ile Gly Val Asp 20 25 7 16 PRT Lactobacillus reuteri 7 Met Ala His Leu Asp Val Trp Asp Ser Trp Pro Val Gln Asp Pro Val 1 5 10 15 8 9 PRT Lactobacillus reuteri 8 Asn Ala Gly Ser Ile Phe Gly Thr Lys 1 5 9 19 PRT Lactobacillus reuteri 9 Val Glu Glu Val Tyr Ser Pro Lys Val Ser Thr Leu Met Ala Ser Asp 1 5 10 15 Glu Val Glu 10 4634 DNA Lactobacillus reuteri CDS (1220)..(3598) RBS (1205)..(1210) modified_base (2702)..(2707) a, c, t, g, other or unknown 10 gttaacaaag acaaaatttt atataattct tcaaattaaa tttcccactg taagaacata 60 aatgggtacc tgtttgatgg gaataatata tttgtaacta accggccggc acctctttct 120 aatgtgccta ggatgcataa tggatgtaaa ttactagatg gcggttttta tacattaacc 180 tcgcaggaga gaaaagaagc aattagtaag gatccatatg cagataaatt tattaggcct 240 tatttaggtg ctaaaaattt cattcatgga actgctaggt actgtatttg gttaaaggac 300 gcaaacccga aagatatcca tcaatcgcca tttatactgg atagaatcaa taaagtagcg 360 gaattcagat cgcagcaaaa aagtaaagat acacaaaaat atgcaaaacg gcccatgcta 420 acaacacgac ttgcctatta tagccacgat gtacatacgg atatgctgat agtacctgca 480 acatcatcgc aacgtagaga atatcttcca attggatatg tttcagaaaa gaatattgtg 540 tcttattcac taatgctaat ccccaatgct agtaatttta atttcggtat tctagaatct 600 aaagttcact atatttggtt aaaaaacttt tgcggtcggt tgaagtccga ttatcgttat 660 tcaaacacta ttatttataa taatttccct tggccgactg ttggtgacaa gccaggamca 720 acaccatctc tgacactcgc tcaaggtata ttaaatactc gcaagctcta tccagacagc 780 tcactggctg atctttatga tccactaaca atgccragtt gaactcgtaa agctcatgaa 840 gccaatgata aagctgttct taaagcatat ggattgagcc ctaaagctac tgagcaagaa 900 atcgtagaac atctatttaa gatgtatgaa aaactgacta aaggtgaaag ataactttgt 960 aaaaccaata ttttataaag acagtaaatg ttaatttgat aaaaacatat atttaataaa 1020 caaaagtgat ataatcaagt agttctttgt attacaaaat acatttaata tctctcagca 1080 ttttgcatac tgggagattt tttattgaca aattgtttga aagtgcttat gatgaaaccg 1140 tgtagaaact aattcaattt gataaacgtt agacatttct gaggaggaag tcattttgga 1200 gtacaaagaa cataagaaa atg tat aaa gtc ggc aag aat tgg gcc gtt gct 1252 Met Tyr Lys Val Gly Lys Asn Trp Ala Val Ala 1 5 10 aca ttg gta tca gct tca att tta atg gga ggg gtt gta acc gct cat 1300 Thr Leu Val Ser Ala Ser Ile Leu Met Gly Gly Val Val Thr Ala His 15 20 25 gct gat caa gta gaa agt aac aat tac aac ggt gtt gct gaa gtt aat 1348 Ala Asp Gln Val Glu Ser Asn Asn Tyr Asn Gly Val Ala Glu Val Asn 30 35 40 act gaa cgt caa gct aat ggt caa att ggc gta gat gga aaa att att 1396 Thr Glu Arg Gln Ala Asn Gly Gln Ile Gly Val Asp Gly Lys Ile Ile 45 50 55 agt gct aac agt aat aca acc agt ggc tcg aca aat caa gaa tca tct 1444 Ser Ala Asn Ser Asn Thr Thr Ser Gly Ser Thr Asn Gln Glu Ser Ser 60 65 70 75 gct act aac aat act gaa aat gct gtt gtt aat gaa agc aaa aat act 1492 Ala Thr Asn Asn Thr Glu Asn Ala Val Val Asn Glu Ser Lys Asn Thr 80 85 90 aac aat act gaa aat gct gtt gtt aat gaa aac aaa aat act aac aat 1540 Asn Asn Thr Glu Asn Ala Val Val Asn Glu Asn Lys Asn Thr Asn Asn 95 100 105 act gaa aat gct gtt gtt aat gaa aac aaa aat act aac aac aca gaa 1588 Thr Glu Asn Ala Val Val Asn Glu Asn Lys Asn Thr Asn Asn Thr Glu 110 115 120 aac gat aat agt caa tta aag tta act aat aat gaa caa cca tca gcc 1636 Asn Asp Asn Ser Gln Leu Lys Leu Thr Asn Asn Glu Gln Pro Ser Ala 125 130 135 gct act caa gca aac ttg aag aag cta aat cct caa gct gct aag gct 1684 Ala Thr Gln Ala Asn Leu Lys Lys Leu Asn Pro Gln Ala Ala Lys Ala 140 145 150 155 gtt caa aat gcc aag att gat gcc ggt agt tta aca gat gat caa att 1732 Val Gln Asn Ala Lys Ile Asp Ala Gly Ser Leu Thr Asp Asp Gln Ile 160 165 170 aat gaa tta aat aag att aac ttc tct aag tct gct gaa aag ggt gca 1780 Asn Glu Leu Asn Lys Ile Asn Phe Ser Lys Ser Ala Glu Lys Gly Ala 175 180 185 aaa ttg acc ttt aag gac tta gag ggg att ggt aat gct att gtt aag 1828 Lys Leu Thr Phe Lys Asp Leu Glu Gly Ile Gly Asn Ala Ile Val Lys 190 195 200 caa gat cca caa tat gct att cct tat tct aat gct aag gaa atc aag 1876 Gln Asp Pro Gln Tyr Ala Ile Pro Tyr Ser Asn Ala Lys Glu Ile Lys 205 210 215 aat atg cct gca aca tac act gta gat gcc caa aca ggt aag atg gct 1924 Asn Met Pro Ala Thr Tyr Thr Val Asp Ala Gln Thr Gly Lys Met Ala 220 225 230 235 cat ctt gat gtc tgg gac tct tgg cca gta caa gat cct gtc aca ggt 1972 His Leu Asp Val Trp Asp Ser Trp Pro Val Gln Asp Pro Val Thr Gly 240 245 250 tat gta tct aat tac atg ggt tat caa cta gtt att gct atg atg ggt 2020 Tyr Val Ser Asn Tyr Met Gly Tyr Gln Leu Val Ile Ala Met Met Gly 255 260 265 att cca aat tcg cca act gga gat aat cat atc tat ctt ctt tac aac 2068 Ile Pro Asn Ser Pro Thr Gly Asp Asn His Ile Tyr Leu Leu Tyr Asn 270 275 280 aag tat ggt gat aat gac ttt tct cat tgg cgc aat gca ggt tca atc 2116 Lys Tyr Gly Asp Asn Asp Phe Ser His Trp Arg Asn Ala Gly Ser Ile 285 290 295 ttt gga act aaa gaa aca aat gtg ttc caa gaa tgg tca ggt tca gct 2164 Phe Gly Thr Lys Glu Thr Asn Val Phe Gln Glu Trp Ser Gly Ser Ala 300 305 310 315 att gta aat gat gat ggt aca att caa cta ttt ttc acc tca aat gat 2212 Ile Val Asn Asp Asp Gly Thr Ile Gln Leu Phe Phe Thr Ser Asn Asp 320 325 330 acg tct gat tac aag ttg aat gat caa cgc ctt gct acc gca aca tta 2260 Thr Ser Asp Tyr Lys Leu Asn Asp Gln Arg Leu Ala Thr Ala Thr Leu 335 340 345 aac ctt aat gtt gat gat aac ggt gtt tca atc aag agt gtt gat aat 2308 Asn Leu Asn Val Asp Asp Asn Gly Val Ser Ile Lys Ser Val Asp Asn 350 355 360 tat caa gtt ttg ttt gaa ggt gat gga ttt cac tac caa act tat gaa 2356 Tyr Gln Val Leu Phe Glu Gly Asp Gly Phe His Tyr Gln Thr Tyr Glu 365 370 375 caa ttc gca aac ggc aaa gat cgt gaa aat gat gat tac tgc tta cgt 2404 Gln Phe Ala Asn Gly Lys Asp Arg Glu Asn Asp Asp Tyr Cys Leu Arg 380 385 390 395 gac cca cac gtt gtt caa tta gaa aat ggt gat cgt tat ctt gta ttc 2452 Asp Pro His Val Val Gln Leu Glu Asn Gly Asp Arg Tyr Leu Val Phe 400 405 410 gaa gct aat act ggg aca gaa gat tac caa agt gac gac caa att tat 2500 Glu Ala Asn Thr Gly Thr Glu Asp Tyr Gln Ser Asp Asp Gln Ile Tyr 415 420 425 aat tgg gct aac tat ggt ggc gat gat gcc ttc aat att aag agt tcc 2548 Asn Trp Ala Asn Tyr Gly Gly Asp Asp Ala Phe Asn Ile Lys Ser Ser 430 435 440 ttc aag ctt ttg aat aat aag aag gat cgt gaa ttg gct ggt tta gct 2596 Phe Lys Leu Leu Asn Asn Lys Lys Asp Arg Glu Leu Ala Gly Leu Ala 445 450 455 aat ggt gca ctt ggt atc tta aag ctc act aac aat caa agt aag cca 2644 Asn Gly Ala Leu Gly Ile Leu Lys Leu Thr Asn Asn Gln Ser Lys Pro 460 465 470 475 aag gtt gaa gaa gta tac tca cca ttg gta tct act ttg atg gct tgc 2692 Lys Val Glu Glu Val Tyr Ser Pro Leu Val Ser Thr Leu Met Ala Cys 480 485 490 gat gag gta nnn nnn aag ctt ggt gat aag tat tat ctc ttc tcc gta 2740 Asp Glu Val Xaa Xaa Lys Leu Gly Asp Lys Tyr Tyr Leu Phe Ser Val 495 500 505 act cgt gta agt cgt ggt tcc gat cgt gaa tta acc gct aag gat aac 2788 Thr Arg Val Ser Arg Gly Ser Asp Arg Glu Leu Thr Ala Lys Asp Asn 510 515 520 aca atc gtt ggt gat aac gtt gct atg att ggt tac gtt tcc gat agc 2836 Thr Ile Val Gly Asp Asn Val Ala Met Ile Gly Tyr Val Ser Asp Ser 525 530 535 tta atg ggt aag tac aag cca tta aat aac tca ggt gtc gta tta act 2884 Leu Met Gly Lys Tyr Lys Pro Leu Asn Asn Ser Gly Val Val Leu Thr 540 545 550 555 gca tca gta cct gca aac tgg cgt act gct act tat tcc tac tat gca 2932 Ala Ser Val Pro Ala Asn Trp Arg Thr Ala Thr Tyr Ser Tyr Tyr Ala 560 565 570 gta cct gta gct ggt cat cct gat caa gta tta att act tct tac atg 2980 Val Pro Val Ala Gly His Pro Asp Gln Val Leu Ile Thr Ser Tyr Met 575 580 585 agt aac aag gac ttt gct tca ggt gaa gga aac tat gca act tgg gca 3028 Ser Asn Lys Asp Phe Ala Ser Gly Glu Gly Asn Tyr Ala Thr Trp Ala 590 595 600 cca agt ttc tta gta caa atc aat cca gat gac acg aca act gta tta 3076 Pro Ser Phe Leu Val Gln Ile Asn Pro Asp Asp Thr Thr Thr Val Leu 605 610 615 gca cgt gca act aac caa ggt gac tgg gtg tgg gac gac tct agt cgg 3124 Ala Arg Ala Thr Asn Gln Gly Asp Trp Val Trp Asp Asp Ser Ser Arg 620 625 630 635 aac gat aat atg ctc ggt gtt ctt aaa gaa ggt gca gct aac agt gcc 3172 Asn Asp Asn Met Leu Gly Val Leu Lys Glu Gly Ala Ala Asn Ser Ala 640 645 650 gcc tta cca ggt gaa tgg ggt aag cca gtt gac tgg agt ttg att aac 3220 Ala Leu Pro Gly Glu Trp Gly Lys Pro Val Asp Trp Ser Leu Ile Asn 655 660 665 aga agt cct ggc tta ggc tta aag cct cat caa cca gtt caa cca aag 3268 Arg Ser Pro Gly Leu Gly Leu Lys Pro His Gln Pro Val Gln Pro Lys 670 675 680 att gat caa cct gat caa caa cct tct ggt caa aac act aag aat gtc 3316 Ile Asp Gln Pro Asp Gln Gln Pro Ser Gly Gln Asn Thr Lys Asn Val 685 690 695 aca cca ggt aat ggt gat aag cct gct ggt aag gca act cct gat aac 3364 Thr Pro Gly Asn Gly Asp Lys Pro Ala Gly Lys Ala Thr Pro Asp Asn 700 705 710 715 act aat att gat cca agt gca caa cct tct ggt caa aac act aat att 3412 Thr Asn Ile Asp Pro Ser Ala Gln Pro Ser Gly Gln Asn Thr Asn Ile 720 725 730 gat cca agt gca caa mct tct ggt caa aac act aag aat gtc aca cca 3460 Asp Pro Ser Ala Gln Xaa Ser Gly Gln Asn Thr Lys Asn Val Thr Pro 735 740 745 ggt aat gag aaa caa ggt aag aat acc gat gca aaa caa tta cca caa 3508 Gly Asn Glu Lys Gln Gly Lys Asn Thr Asp Ala Lys Gln Leu Pro Gln 750 755 760 aca ggt aat aag tct ggt tta gca gga ctt tac gct ggt tca tta ctt 3556 Thr Gly Asn Lys Ser Gly Leu Ala Gly Leu Tyr Ala Gly Ser Leu Leu 765 770 775 gcc ttg ttt gga ttg gca gca att gaa aag cgt cac gct taa 3598 Ala Leu Phe Gly Leu Ala Ala Ile Glu Lys Arg His Ala 780 785 790 tagagtaaaa aaacatcctc cactcaagtt acaagtagga taatatgtat tatttctacg 3658 cytagtcaag aggrattact ggacatannn nnnnnnnnnn tccagttacc aagtggaata 3718 tagtattatt ccacgctagt caggaggatt actgacatta ttggctacat ggccggtagt 3778 cctcttttct tttgtgacga attgtcaaac caagtgcaac ggtttctcaa aaaacacctc 3838 atatggggtt tcataattta acacttttcg aggacggcgg ttcagctgat gttggcagaa 3898 actgacgtcc ttatctgtat aatcatcaat attagccctt ttaggaaagt attccctaat 3958 tagsccattg gtattttcat tgggtcctct ttcctctggt gaatagggat ctggccaata 4018 gatagctact cctaaacgtc ctcgaatatc attcaagcca agaaattcac gcccatgatc 4078 tggagtcaat gaatggacaa attctttagg aatagaccct aagagatcaa ttaagccctg 4138 atatttgaat tcggagaagg ggagttgtcc aacaattgcc gttataatac cagggttaat 4198 acggccctgg gcctctacgg taatattgta tttttggctc agatcagtga tagaaaccca 4258 cagatttagc ttgccggtgg agtgctgctt gaagtcttca attacttcgt taccatgttt 4318 gattgctaat ctgatgtgtc gttgttgtgg tgtagtaggc atcataccac ctcctcataa 4378 aataaggtat aacaggaatt tcttgtacta tatgatcctt ccaatataat aatattaggc 4438 cgataagaaa tgaccagcta ccatttcttg atgcttagtg aatataatcg gatgatacgt 4498 cacccctcaa caatccaatt tcacggaggt gagtaatcat gccgagagct aggaatgatt 4558 ggaggaacga acacggtcca tgcggcagtg gctatttgga ttttagccaa agcagcgtta 4618 ctgcttgcaa aagctt 4634 11 792 PRT Lactobacillus reuteri MOD_RES (495)..(496) Any amino acid 11 Met Tyr Lys Val Gly Lys Asn Trp Ala Val Ala Thr Leu Val Ser Ala 1 5 10 15 Ser Ile Leu Met Gly Gly Val Val Thr Ala His Ala Asp Gln Val Glu 20 25 30 Ser Asn Asn Tyr Asn Gly Val Ala Glu Val Asn Thr Glu Arg Gln Ala 35 40 45 Asn Gly Gln Ile Gly Val Asp Gly Lys Ile Ile Ser Ala Asn Ser Asn 50 55 60 Thr Thr Ser Gly Ser Thr Asn Gln Glu Ser Ser Ala Thr Asn Asn Thr 65 70 75 80 Glu Asn Ala Val Val Asn Glu Ser Lys Asn Thr Asn Asn Thr Glu Asn 85 90 95 Ala Val Val Asn Glu Asn Lys Asn Thr Asn Asn Thr Glu Asn Ala Val 100 105 110 Val Asn Glu Asn Lys Asn Thr Asn Asn Thr Glu Asn Asp Asn Ser Gln 115 120 125 Leu Lys Leu Thr Asn Asn Glu Gln Pro Ser Ala Ala Thr Gln Ala Asn 130 135 140 Leu Lys Lys Leu Asn Pro Gln Ala Ala Lys Ala Val Gln Asn Ala Lys 145 150 155 160 Ile Asp Ala Gly Ser Leu Thr Asp Asp Gln Ile Asn Glu Leu Asn Lys 165 170 175 Ile Asn Phe Ser Lys Ser Ala Glu Lys Gly Ala Lys Leu Thr Phe Lys 180 185 190 Asp Leu Glu Gly Ile Gly Asn Ala Ile Val Lys Gln Asp Pro Gln Tyr 195 200 205 Ala Ile Pro Tyr Ser Asn Ala Lys Glu Ile Lys Asn Met Pro Ala Thr 210 215 220 Tyr Thr Val Asp Ala Gln Thr Gly Lys Met Ala His Leu Asp Val Trp 225 230 235 240 Asp Ser Trp Pro Val Gln Asp Pro Val Thr Gly Tyr Val Ser Asn Tyr 245 250 255 Met Gly Tyr Gln Leu Val Ile Ala Met Met Gly Ile Pro Asn Ser Pro 260 265 270 Thr Gly Asp Asn His Ile Tyr Leu Leu Tyr Asn Lys Tyr Gly Asp Asn 275 280 285 Asp Phe Ser His Trp Arg Asn Ala Gly Ser Ile Phe Gly Thr Lys Glu 290 295 300 Thr Asn Val Phe Gln Glu Trp Ser Gly Ser Ala Ile Val Asn Asp Asp 305 310 315 320 Gly Thr Ile Gln Leu Phe Phe Thr Ser Asn Asp Thr Ser Asp Tyr Lys 325 330 335 Leu Asn Asp Gln Arg Leu Ala Thr Ala Thr Leu Asn Leu Asn Val Asp 340 345 350 Asp Asn Gly Val Ser Ile Lys Ser Val Asp Asn Tyr Gln Val Leu Phe 355 360 365 Glu Gly Asp Gly Phe His Tyr Gln Thr Tyr Glu Gln Phe Ala Asn Gly 370 375 380 Lys Asp Arg Glu Asn Asp Asp Tyr Cys Leu Arg Asp Pro His Val Val 385 390 395 400 Gln Leu Glu Asn Gly Asp Arg Tyr Leu Val Phe Glu Ala Asn Thr Gly 405 410 415 Thr Glu Asp Tyr Gln Ser Asp Asp Gln Ile Tyr Asn Trp Ala Asn Tyr 420 425 430 Gly Gly Asp Asp Ala Phe Asn Ile Lys Ser Ser Phe Lys Leu Leu Asn 435 440 445 Asn Lys Lys Asp Arg Glu Leu Ala Gly Leu Ala Asn Gly Ala Leu Gly 450 455 460 Ile Leu Lys Leu Thr Asn Asn Gln Ser Lys Pro Lys Val Glu Glu Val 465 470 475 480 Tyr Ser Pro Leu Val Ser Thr Leu Met Ala Cys Asp Glu Val Xaa Xaa 485 490 495 Lys Leu Gly Asp Lys Tyr Tyr Leu Phe Ser Val Thr Arg Val Ser Arg 500 505 510 Gly Ser Asp Arg Glu Leu Thr Ala Lys Asp Asn Thr Ile Val Gly Asp 515 520 525 Asn Val Ala Met Ile Gly Tyr Val Ser Asp Ser Leu Met Gly Lys Tyr 530 535 540 Lys Pro Leu Asn Asn Ser Gly Val Val Leu Thr Ala Ser Val Pro Ala 545 550 555 560 Asn Trp Arg Thr Ala Thr Tyr Ser Tyr Tyr Ala Val Pro Val Ala Gly 565 570 575 His Pro Asp Gln Val Leu Ile Thr Ser Tyr Met Ser Asn Lys Asp Phe 580 585 590 Ala Ser Gly Glu Gly Asn Tyr Ala Thr Trp Ala Pro Ser Phe Leu Val 595 600 605 Gln Ile Asn Pro Asp Asp Thr Thr Thr Val Leu Ala Arg Ala Thr Asn 610 615 620 Gln Gly Asp Trp Val Trp Asp Asp Ser Ser Arg Asn Asp Asn Met Leu 625 630 635 640 Gly Val Leu Lys Glu Gly Ala Ala Asn Ser Ala Ala Leu Pro Gly Glu 645 650 655 Trp Gly Lys Pro Val Asp Trp Ser Leu Ile Asn Arg Ser Pro Gly Leu 660 665 670 Gly Leu Lys Pro His Gln Pro Val Gln Pro Lys Ile Asp Gln Pro Asp 675 680 685 Gln Gln Pro Ser Gly Gln Asn Thr Lys Asn Val Thr Pro Gly Asn Gly 690 695 700 Asp Lys Pro Ala Gly Lys Ala Thr Pro Asp Asn Thr Asn Ile Asp Pro 705 710 715 720 Ser Ala Gln Pro Ser Gly Gln Asn Thr Asn Ile Asp Pro Ser Ala Gln 725 730 735 Xaa Ser Gly Gln Asn Thr Lys Asn Val Thr Pro Gly Asn Glu Lys Gln 740 745 750 Gly Lys Asn Thr Asp Ala Lys Gln Leu Pro Gln Thr Gly Asn Lys Ser 755 760 765 Gly Leu Ala Gly Leu Tyr Ala Gly Ser Leu Leu Ala Leu Phe Gly Leu 770 775 780 Ala Ala Ile Glu Lys Arg His Ala 785 790 12 24 DNA Artificial Sequence Description of Artificial Sequence Primer 12 ctgataataa tggaaatgta tcac 24 13 26 DNA Artificial Sequence Description of Artificial Sequence Primer 13 catgatcata agtttggtag taatag 26 14 24 DNA Artificial Sequence Description of Artificial Sequence Primer 14 gtgatacatt tccattatta tcag 24 15 26 DNA Artificial Sequence Description of Artificial Sequence Primer 15 ctattactac caaacttatg atcatg 26 16 38 DNA Artificial Sequence Description of Artificial Sequence Primer 16 ccatggccat ggtagaacgc aaggaacata aaaaaatg 38 17 38 DNA Artificial Sequence Description of Artificial Sequence Primer 17 agatctagat ctgttaaatc gacgtttgtt aatttctg 38 18 21 DNA Artificial Sequence Description of Artificial Sequence Primer 18 gaygtntggg aywsntgggc c 21 19 23 DNA Artificial Sequence modified_base (3) a, c, t, g, other or unknown 19 gtngcnswnc cnswccayts ytg 23 20 22 DNA Artificial Sequence Description of Artificial Sequence Primer 20 gaatgtaggt ccaatttttg gc 22 21 22 DNA Artificial Sequence Description of Artificial Sequence Primer 21 cctgtccgaa catcttgaac tg 22 22 23 DNA Artificial Sequence Description of Artificial Sequence Primer 22 arraanswng gngcvmangt nsw 23 23 23 DNA Artificial Sequence Description of Artificial Sequence Primer 23 tayaayggng tngcngargt naa 23 24 22 DNA Artificial Sequence Description of Artificial Sequence Primer 24 ccgaccatct tgtttgatta ac 22 25 24 DNA Artificial Sequence Description of Artificial Sequence Primer 25 aaytataayg gygttgcryg aagt 24 26 21 DNA Artificial Sequence Description of Artificial Sequence Primer 26 taccgnwsnc tacttcaact t 21 27 17 PRT Lactobacillus reuteri 27 Tyr Asn Gly Val Ala Glu Val Lys Lys Arg Gly Tyr Phe Tyr Ala Arg 1 5 10 15 Thr 28 17 PRT Lactobacillus reuteri 28 Tyr Asn Gly Val Ala Glu Val Asn Thr Glu Arg Gln Ala Asn Gly Gly 1 5 10 15 Ile 29 14 PRT Bacillus amyloliquefaciens 29 Gly Leu Asp Val Trp Asp Ser Trp Pro Leu Gln Asn Ala Asp 1 5 10 30 14 PRT Bacillus subtilis 30 Gly Leu Asp Val Trp Asp Ser Trp Pro Leu Gln Asn Ala Asp 1 5 10 31 14 PRT Streptococcus mutans 31 Asp Leu Asp Val Trp Asp Ser Trp Pro Val Gln Asp Ala Lys 1 5 10 32 14 PRT Streptococcus salivarius 32 Glu Ile Asp Val Trp Asp Ser Trp Pro Val Gln Asp Ala Lys 1 5 10 33 16 PRT Bacillus amyloliquefaciens 33 Gln Thr Gln Glu Trp Ser Gly Ser Ala Thr Phe Thr Ser Asp Gly Lys 1 5 10 15 34 16 PRT Bacillus subtilis 34 Gln Thr Gln Glu Trp Ser Gly Ser Ala Thr Phe Thr Ser Asp Gly Lys 1 5 10 15 35 16 PRT Streptococcus mutans 35 Leu Thr Gln Glu Trp Ser Gly Ser Ala Thr Val Asn Glu Asp Gly Ser 1 5 10 15 36 16 PRT Streptococcus salivarius 36 Asp Asp Gln Gln Trp Ser Gly Ser Ala Thr Val Asn Ser Asp Gly Ser 1 5 10 15 37 11 PRT Bacillus amyloliquefaciens 37 Lys Ala Thr Phe Gly Pro Ser Phe Leu Met Asn 1 5 10 38 11 PRT Bacillus subtilis 38 Gln Ser Thr Phe Ala Pro Ser Phe Leu Leu Asn 1 5 10 39 11 PRT Streptococcus mutans 39 Asn Ser Thr Trp Ala Pro Ser Phe Leu Ile Gln 1 5 10 40 11 PRT Streptococcus salivarius 40 Lys Ser Thr Trp Ala Pro Ser Phe Leu Ile Lys 1 5 10 

We claim:
 1. A process of producing one or more fructans selected from fructans having P(2-1) linked D-fructosyl units and fructans having β(2-6) linked D-fructosyl units, comprising subjecting a fructose source selected from sucrose, raffinose, stachyose and fructo-oligosaccharides to a Lactobacillus strain containing and capable of expressing at least one protein having fructosyltransferase activity, under non-growth conditions, to obtain a mixture containing said one or more fructans.
 2. The process of claim 1 for producing from fructans having β(2-1) linked D-fructosyl units, wherein said Lactobacillus strain contains at least one protein having fructosyltransferase activity and exhibiting at least 85% amino acid identity, as determined by the BLAST algorithm, with an amino acid sequence of SEQ ID No.
 1. 3. The process of claim 1 for producing from fructans having β(2-6) linked D-fructosyl units, wherein said Lactobacillus strain contains at least one protein having fructosyltransferase activity and exhibiting at least 85% amino acid identity, as determined by the BLAST algorithm, with an amino acid sequence of SEQ ID No.
 11. 4. The process according to claim 1, further comprising separating said fructans from said Lactobacillus strain and adding a food or beverage composition to said fructans, to obtain a prebiotic composition.
 5. The process according to claim 1, further comprising adding a food or beverage composition to said mixture, to obtain a synbiotic composition.
 6. The process according to claim 1, further comprising chemically modifying said one or more fructans by simultaneous 3- and 4-oxidation, by 1- or 6-oxidation, phosphorylation, acylation, alkylation, hydroxyalkylation, carboxymethylation, epoxyalkylation, aminoalkylation of one or more anhydrofructose units of said fructans, or by hydrolysis.
 7. A process of producing a chemically modified fructan having at least 100 β(2-1) linked or β(2-6) linked D-fructosyl units, comprising chemically modifying said fructan by simultaneous 3- and 4-oxidation, by 1- or 6-oxidation, phosphorylation, acylation, alkylation, hydroxyalkylation, carboxymethylation, epoxyalkylation, aminoalkylation of one or more anhydrofructose units of said fructans.
 8. The process of claim 7, wherein a fructan having β(2-6) linked D-fructosyl units is chemically modified by 1-oxidation using a nitroxyl catalyst.
 9. The process of claim 8, wherein partial 1-oxidation of a fructan having β(2-6) linked D-fructosyl units is carried out to obtain a product containing both aldehyde and carboxylic functions.
 10. A chemically modified fructan having at least 100 p(2-6) linked D-fructosyl units, containing between 1 and 100 1-aldehyde/carboxyl groups per 100 D-fructosyl units.
 11. The modified fructan of claim 10, containing between 1 and 50 1-aldehyde groups and between 1 and 50 1-carboxyl groups per 100 D-fructosyl units. 